I thought "headphone socket" the instant you switched the unit on. But corrosion hidden by the socket isn't something that I'd have thought about immediately, so you are forgiven. I'd add that in my experience of repairing similar equipment, the audio chip usually fails catastrophically with a burn mark or visible hole.
You need a signal tracer. That would have sorted this out quick. Power it up open and trace the audio path till it turns up dead. I FIND YOU! Rotten little gremlin. And gitter fixed. No more KNACKERS. Also Pro Tip, use lead solder... Its good for your brain and the environment and no TIN WHISKERS. Also you don't need to clean up the flux so completely. Just wipe it with an alcohol wipe if there is excess. Lots of boards out there with tons of flux on them. All works good. Save your time. You are not someone elses maid.
A tip: the Amp chip got power and audio in but no audio out. That could either mean it is broken (as you thought) or that it was told to not output the audio. With the data sheet you would have been able to test it. The chip is quite simple. There is the mute and the standby input. Either of those will be enabled from the board or another chip when you plug the headphone in. So you could have measured that on those pins before you replaced the chip. So what I am saying is take one more look at the data sheet. That being said: great fix and it is totaly understandable that you thought it was the audio chip. Thought so too until I saw the remaining time.
Thanks Daniel, maybe this is where a scope could have been used on those pins to see if I could see the signal switch high or low when the headphones were plugged in 👍👍👍
@@Mymatevinceyou kept mentioning mute but never checked the mute pin i really thought you where going to have it. I only had some prcognition to the issue because I have used tpa chips before, you don't need a scope the mute/standby pins are high low signaling so a test with the dmm would work. (Pin high or low and refrence the data sheet to see what high and low is.) I probably would has assumed a fault in the mute circuit and just removed it or installed a manual mute. Also my fault finding skills aren't up to your level, Although a mute circuit is needed for anti pop on startup. P.s. in some places when you just need to check if there is an analog signal and not know the what the siginal is you can just mesure the ac voltage. Line level audio is ~2v headphones are anywhere from 0-2v on most devices.
My friend. I have been an audiophile for forty years and I watched your video with great interest and zero understanding whatsoever. Your fluency in electronic engineering is masterfull. I heard every word you spoke but the meaning utterly escaped me. I feel such a dunce. Huge respect to you, however, because i watched your video all the way through just so that it sank in just how stupid I really am.
One thing you should consider buying is an oscilloscope, you can then use to confirm audio signals from the output of the amplifier chip, follow the traces round and see where the audio signals are lost. You can also use it to check the audio signal waves are correct using the diagrams often found in service manuals, as well as using for things like tape deck calibration, head alignment and all sort so of other checks very useful for electronics repair.
@@rogerphelps9939You can even get an inexpensive one that plugs into the USB or lightning port on a smartphone or tablet, and uses that device's display and touch screen to control the 'scope.
@@rogerphelps9939 - I used to fix a lot of radios and he should have a signal tracer. Better than a scope because it can indicate data or actual audio or some other signal. And invaluable tool
I must admit i was shouting at the screen at the very start " get a jack in the socket and give it a wiggle" you wouldn't believe how common it is lol, you got there in the end but always the first thing i do with " no sound" faults 😊
The signal from the jack goes to the Mute pin on the chip to mute the speaker out and play only out the phones.This is not the same as what the mute button does on the remote. I was yelling at the screen the whole time :-)))) Love your enthusiasm, it is contagious!
I was literally screaming at the screen as soon as you dismissed the jack at the beginning. I didn't feel that you had tested that properly in the first place. The identical jack beside it was the perfect reference to thorough testing.
Hi Vince, it is so so nice to see your genuine joy from being able to fix something. It made me smile. That joyfulness is infectious, in a good way! Thank you!
Love the "YEEEEEEES" lol! A fun watch, it's frustrating when you miss the obvious - we've all done it!!!! You've covered two repairs in one really, because there will be units of that out there where there's no sound at all, and it will be that amp IC probably!
Great job on the repair. You've given me the incentive to repair the home cinema remote control that had a battery that decided to leak and stop it working. Replacements are only available in the USA or China for £30 for my specific make. It is back up and running after white vinegar and IPA. I did desolder and resolder the components around the problem to ensure a deep clean of everything - yes, the desoldering gun (that I got after winning some money) is a game changer.
Thank you for doing this video. I actually work for Bose tech support and deal with these all the time. It's nice to have an actual look inside and get an understanding of what goes on in the repair centre 👍 I'm also right at the start of my electronics learning curve, so watching these vids really helps get to grips with what everything does. I've learnt a lot from vids like this ❤
False starts are always a good learning experience, frustrating at the time but always a memorable lesson. The most valuable experience I got out of my uni electronics laboratory class was that connectors and cables are your enemy - nothing like spending 90 minutes tearing apart a circuit, swapping out instruments, etc. only to find that the actual fault was a worn cheap cable between the oscilloscope and the circuit. Videos like yours show how much abuse cables and connectors take and how vulnerable they are to mechanical and chemical (corrosion) damage. Add in the failure rates of MOSFETs and ceramic SMD capacitors and it's amazing how much dead gear is easily recoverable.
Well done! You are understandably wary of high voltages around mains inputs. Don't forget that you can power a unit like this using your bench power supply instead while testing.
I was "I hate to say I told you so, but I told you so...". Immediately suspected the switching function on the jack, instead of the amp IC. Usually mechanical components fail before electronics... Glad you fixed it in the end and it wasn't a 100 € part. At least you've got a spare now ;-)
Having fixed many of these style Bose Radio CD's in the past the most common failure is those silver SMD electrolytic caps. They leak and cause various issues including No Sound, CD Not Reading, CD Not ejecting/loading, burned amp chip and i'm sure other strange issues which I have yet to come across. If you truly want this to be reliable a replacement of these caps is a must!
last week i saw what i thought was a Bose Wave radio sitting beside a dumpster. i yelled STOP! at my brother and jumped out of the car on the side of the road and ran back to get it.... it was an under cabinet radio/CD player from someones kitchen. Not Bose... it was GE(general electric) brand. It's now an under-the-toolbench garage radio. :)
I have the same problem, and I'm so glad that you took the first step on the moon for me and I can't wait to stop watching this video so I can go run and fix mine. Man I love you lol thank thank you for showing this video. Great job 👏 👍 👌
That was beautifully done. That one could have quite easily fooled a professional... (like me).. Thank you Vince for teaching an old hand to persevere! Even though that was the very first thing I would have checked... I may have had trouble.
I remember first models of these Bose radios came out in the mid 1990s. These are not just the 2 speakers, but there are specially designed sound chambers behind these speakers that make the sound sound "bigger and spacier." I remember my engineering teacher had a diagram of these chambers on his door to his office :). It was supposed to be new tech in audio technology.
Emperor's new clothes. Just like quadrophonic Hi Fi was for people with 4 ears. It is BS I'm afraid. Big names like Bose and B&O made their fortune by feeding the Hi Fi snobs with basic stuff wrapped up in weird cabinets.
I’m a huge fan of your videos. You followed a logical fault finding path, but as soon as I saw it work on headphones I expected the headphone jack based on experience. Congrats on getting it working and I’m sure that TDA chip will be useful another day, it’s a small price to play.. we all know the feeling of changing a suspect component only to find it makes no difference.
The difference with the Bose, is that you will hear it almost the same everywhere in the room. I remember the first time I played the demo disc, I was wowed, but that novelty soon wore off. But I do remember thinking that it filled the room better than other equipment I had.. All Bose products are way too bassy and that is a massive minus for me. But great job with the first guess and being proved right. Love this channel
Vince your fault finding skills are absolutely incredible. Im sure philips use that chip in there car stereo i may be wrong tho but i have i have definitely come across and replaced that chip a few times over the years but it was a long time ago i cant quite remember....i was convinced it was the ic as well
You are too kind Stacie! I think a pro would have measured the chip with a scope and noticed no difference was made when the headphones were plugged in, and worked out what was what pretty quickly. I scratched my head on this for hours upon hours 😂 Still perseverance got there in the end.
I'm 22 mins into the video. You're about to check for output from the TDA chip. I'm guessing there is none. It might be worth checking the logic level into the mute pin and also going back to the audio out jack and checking where it's sound comes from, as you know the earphones work. My guess is it's either a mute fault or a problem with the audio out socket not making contact when there are no earphones plugged into it. Right now I'm going back to the video to see if I'm right... Reached the end - well I was nearly right. The earphone socket works by resistance and mutes the main output from the sound chip. In many older items a faulty earphone socket causing no speaker sound ( the socket being open circuit when nothing is plugged in it) is a common fault. Great video. It made me laugh to see your absolute joy at fixing it. 😃
The pressure of you plugging it in and out was causing the ingress to shift, that's why it worked briefly when unplugging the headphones! Liquid ingress is a tricky beast! Just like bad grounds! Great job!
At least you’re finding plenty of uses for your expensive Kapton polyimide tape! Good stuff! Many other channels leave out the prodding about with the probes but that leaves out the beginner / intermediate level knowledge that surely everyone needs to attain sometime. So you’ve made this one a very comprehensive job! Accolades, friend! Haters will always hate, but you’ve made this so valuable to those of us who need to learn from it!! …and you’ve captured the very moment when you realized your accomplishment! That excitement is the stuff of a good life of value with achievements!
We learn from you. The suppliers mimimum order costs always wind me up when they have the most sophistocated logistics available. CPC used to have a trade counter on North road, Preston, oh that was 40 years ago, same with Farnell in Leeds, not sure if they still have them if your lucky enough to live nearby. Fixed some skiped Kern lab scales this week, someone must have plugged wrong psu in, not 12V centre +, shorted the protection diode and was scrapped off. £900 thrown away for a component designed to protect , and it did. Pleasure to watch. Great result.
I was nearly certain that the problem was in the headphone jack. I was so flustered when you eliminated it, I skipped to the end. Relieved that you found the real problem.
Good Job Vince 👍 I had been thinking something to do with the headphone jack. The TDA chips usually fail short and get hot or blow a fuse or such. I thought the socket might be faulty, but didn't expect corrosion underneath it. Well spotted. Seems we have both did a video on Audio Equipment, and in both repairs the root the cause was corrosion! Keep up the great work. Best wishes Mick.
If there are cooling vents on the top check for corrosion, that's where the water, gin & tonic, beer, coffee and tea tends to go. A lot of these Bose units were used as bedside radios and a simple spill with a bedtime drink in the middle of the night will be forgotten about over the years - especially when handed down the generations.
Vince! Perfect timing. I got one of these on my bench right now. Super bad corrosion on mine. But it's in the same area you're working on. So I'm learning today.
I've had exactly the same. I thought it was leaky SMD electrolytic capacitors but I'm wondering if the location is such that an accidentally spilled drink could concentrate around that area. I remember when I replaced the capacitors I didn't get the usual cats pee smell you get when desoldering.
As others have said, I was virtually shouting at the screen "check the mute signal!" after I had checked the datasheet quickly! I thought at first that headphone jack would be one with switch contacts - the "cheap" way of muting the speakers is to route the signals through extra contacts on the jack which are open circuited when the headphone jack is inserted. Such mechanical switching is well known to be unreliable, so would be a first assumption. However, when you showed the jack socket connections, it was obvious it was not that sort of socket. Well done for eventually finding the problem. What I can't remember seeing before is those "spark gap" traces on a headphone circuit. I would not like to be wearing headphones when that spark gap flashed over - with that sort of gap it would probably be several hundred volts!
Great Channel! Vince, if you replace Parts mounted on Heatsink think about mounting them first before you solder them! That will reduce Stress on the Part and prevent from cracking solder Points. Also bend Legs if straighr mounted to give some Relief when getting warm/cold,.... Thank you for your great Videos!
I was actually waiting for the part where the screw wouldn't go in but I think he got lucky on this occasion. I've seen some real "engineer" bodges in the past where this happened and whoever did the job just left the screw out and the IC without any heatsink contact at all.
Great fix and experience. I really thought at the beginning you would remove the earphones jack, then we wouldn't enjoy all the tests and findings 😊 awesome video as always MMV!
i repaired a lot of these back in the days... I worked in a Hotel with 250 of these things in it. I love the sound and most of the time the guests ripped something out of em.
Great result, I've overlooked the simple fault and have pulled things completely apart many times, I feel such a twat spending hours only to find it should have been a 10 minute repair
I watched this one last night and I was thinking- why doesn't he use a signal generator, injector etc- which would have proved the TDA chip but then when it was tested and didn't work, I had to admit- a signal gen wouldn't have found that fault! Well done, that was edge of seat stuff in the end!
I think the "mute" pin was the key here. A check on the datasheet would show whether it gets pulled high or low to disable the output. A quick check with the meter there would have probably revealed all.
You had it right from the start it's always the places you don't see causing an issue when liquid damage is involved great fix vince need one for yourself now 😅
Great video. I had a hunch that it might be the audio jack since the chip was getting power and didn’t seem to get hot (based on no voltage drop at the input). Enjoyed this video (and your other repair videos)!
Great job My Mate VINCE! I do like the red mat I grew up on Weller that is what my father had. I keep my 90% in a small 2oz spray bottle good for projects great for old guys like me with wobbly hands 🙂, have a nice day!
Good news, the red mat isn't an eye sore. As for the audio issue, glad you got it sorted though sad you missed such a basic clue. Sound quality though, Bose "No highs, No Lows. Must be Bose"
A lot of this type of repair relies on experience and familiarity. I came across a very similar problem involving a TDA dual amp chip in studio PPM and monitoring set. In just the same way the unit worked through headphone, but would not work through the built in speaker. I have learnt that before removing a chip if possible it's always worth checking all the pins for their operation. In my case I found the lack of speaker output was due to the standby pin being active, which was controlled by a contact in the headphone socket, which wasn't closing when the jack plug was pulled out. There was also another problem with mine, and its something that has happened on three separate items of 1990's equipement, and that has been SMD resistors values drifting very high. Worth bearing in mind.
I own a B&W and still a great piece of kit that also looks good , mine did have a well known buzzing sound and then the sound died, sent it off to B&W and fixed it for £80 and that included posting what a fantastic company to be able to fix it at that price not many will do that. I think the problem was a capacitor blew a well known problem. That Bose is such a classic remember those from growing up and wanting one.
@@6581punk I’m more of a b&w fanboy own zeppelin a Z2 ( a brilliant little speaker ) and 2 style of headphones on your ear and in your ear and love the sound setup by B&W
I had one with loud buzzing and found bad corrosion all round the IC and a crack in the IC front. I thought it was from leaky SMD electrolytics around the chip and replaced them at the same time, but I actually think the owner wasn't honest and had actually spilt beer inside.
When we get a product back for repair at work, the first thing we do is inspect the board. We've seen all kinds of corrosion, some I can't even explain. My favorite was when water dripped int he unit through concrete for several years. Ate so much of the copper off the board....So on a jack like that, instead of breaking the audio lines, it generates a logic level output to signal if something is plugged in. Usually these are high impedance lines (compared to the audio signals and might use a 10K or even 100K pill-up resistor, or perhaps a weak current source internal to the chip it is driving. With a 10K pull up resistor, even something on the order of 5K resistance from the corrosion might be enough to cause the problem you found. One other thing to look out for and tuck into memory. If someone else worked on something and used water soluble solder and failed to clean it, the same problem can occur but is even less visible. Cleaning water soluble solder with IPA can be as bad as not doing anything with it, it must be cleaned with water first. I've seen this four or five times now. In fact, the one switching regulator I use in designs will not function properly until the water soluble solder is totally cleaned off. I mention all of this because it can be a very difficult problem to troubleshoot. I enjoyed the video. Keep fixing more things and add to your knowledge base. I also agree with the post about getting an oscilloscope. simple 2 channel digital scopes are dirt cheap these days and surprisingly decent. I have a $350 four channel Rogol at home and it has impressed me for the cost. It even does a few things better than my Tek. Also, I would recommend an isolation transformer. It can save you and especially a scape which normally is grounded to earth ground. Above all, have fun and be safe. I 100% agree with covering the mains voltage like you did, just in case, especially with 240VAC.
Great video. I would also have thought it's the chip :D Thanks to your old video I've also saved an old Zeppelin recently and I love it. The seller said that the manufacturer doesn't have spare parts for them anymore and since they just swap parts instead of doing real repairs, like most manufacturers, there should be many around these days to rescue :) When it comes to order some extra chips to get a better value out of the high handling and shipping fees: I had to replace the Injoinic IP5306 recently a few times so they might be something worth to have spares from. They're pretty cheap, but common in battery powered electronics from China. I had them often in LED lanterns with USB-C charging. It's a 1S Lipo Charging chip that can also create a 5V 2A Output and display the battery capacity. Especially when people try to plug a micro usb cable into the USB-C port or short the contacts they sometimes fail.
Such a sneaky fault wow, the signs really threw me for a loop too. Fantastic fix Vince👍 And don't forget to do a visual inspection of the board and components always first. But maybe you do but cut it out of the video
These things are expensive for a reason as they deliver good power and 'fill' the room with sound. Well done for perservering with it and maybe next time go with your first gut instinct. 😁👍
Around a third of the way into this video I found myself yelling at the TV, screaming "No, no, no!". I think the neighbors may have heard me. 😆 Why was I reacting that way? Well, aside from my obvious emotional issue, you had ignored the contradictory fact that the headphones were working when you diagnosed a failed audio amplifier chip. In order for the headphones to work but the amplifier chip to have failed, there would have had to have been another stereo amplifier chip or a pair of op amps in the circuit, powering the headphones. But we knew there were no such components. If you had access to a schematic, I'm sure you would have noticed that the power amplifier chip you replaced did in fact feed the headphone jack, which would have instantly ruled out that chip as the problem just a few moments into the diagnosis. Oh well, live and learn -- and your video was informative as you worked your way through. Glad to see the Bose finally working in the end.
I thought it was the caps that feed the audio to the main IC, as I've had a few Bose audio goodies from the 1990s with dried out or shorted caps. Alas corrosion shorting the mute, even easier fix😂
Bose wave technology is in the black box that holds the speakers, it is multi curved like a wave to enable bass port exit out the back of the unit, so when put up against a wall it generates more bass reflex. Smart design and it goes back to the V1 model.
Great that you worked it out. It's always worth cheeking the mute on the audio ic. Looking at what you were doing it was clear that the headphone socket has some basic switch function that activates the mute function on the main audio amp ic. I think the headphones are feed from another ic. But nice another piece of equipment saved from landfill. 👍
I'd be wary of using pc heatsink paste, for example MX4000 as these contain silver particles that can short out an audio transistor if the can of the transistor shouldn't be connected the heatsink electrically. Also it can short out the pins on the chip if used over zealously. Just use regular silicone based white paste. You won't find the former heatsink paste in any audio consumer electronics. You could then be in the same situation where your multimeter doesnt show a short on continuity but still a short on ohms reading.
Aww yes!!! :D What a great fix!! And you have some spares for a next project. Hahah. 😅 I think that chip is quite common in audio products, i hope you find a project to have it used!!
44:44 as you said, you're not an audio guy, but you may be interested to hear that amongst some audio guys, BOSE is considered an acronym for "Buy Other Sound Equipment". Make of that what you will! 😂 Awesome video, as always, and a great fix, too. Great job, Vince.
Good job of fault tracing. I've had enough problems like this on my own equipment over the years, usually with the 4th contact that signals connection, that the first thing I'd suspect is the jack socket. Knowing there had been water ingress, the first thing I'd have done is desoldered the headphone jack, as you did. Also a quick check I'd try would have been to desolder jacks, compare them and then swap them. I know one's input and the other output, but I'd bet they were the same just to keep parts inventory simpler. Yes, wherever you have board mounted components like that there's a gap for capillary action to trap water and promote corrosion. With my eyesight I might have missed that. Mind you I'd also have been signal tracing with my oscilloscope. On cheaper systems the contacts will oxidise with age, so I'd have tried Deoxit too. I am surprised the contacts aren't gold flashed, Bose is expensive enough ! My next project is a laptop in a nursing home that's had plenty of water and tea spilled on it, plus the power lead pulled to the point the plug is bent. I might get lucky and fix it ;) If not it's spares.
Hi Vince, Great work you've done. That something so simple can (eventually) lead you so far away from the real problem. You handled it well by not first measuring the entire device, which would take hours. Looking forward to your next video! Greetings Marcel
I bought a older version on eBay as not working. The cd drive had failed and wouldn't load . It was a horrible yellowed with age cream and I got it very very cheap. After watching a few videos of taking the. Whole thing apart I started on mine. Lid off was pretty simple and it was then I discovered the cd fault. The previous owner had tried to load 2 CDs. Maybe they had stuck together, maybe they hadn't realised there was already one in there, But, with a pair of long nose pliers I pulled the disks out ad it worked perfectly. The shell I scrubbed with sugar soap, masked the screen and cd slot, and sprayed it Matt black. Three years on and it's still quite happy.
NGL, I suspected it was the jack as you have had something similar a few months ago, although that was a jack fault and not an under the jack fault lol. Good fix Vince
You should have check the mute pin and compare with data sheet for the IC.Maybe it was muted by that corosion .the check for the mute with the remote control was irelevant.Big like for your videos.
I have the same issues with IPA. Ended up using some of those small spray bottles. Can spray onto the surface you are working on or the cotton bud or brush. Slightly more hassle but never spilt any since.
In my experience in fixing things like this, it is not normally the amplifier chip but some other reason like an earthing fault or resistance on the mute input, etc so I was not surprised when your chip replacement did not work. Been there done that.
I was screaming measure the standby/mute voltages on the chip. In some audio amplifiers it’s quite normal to switch the audio using the headphones to either the speakers or the headphones via a suitable reducing resistor. But your socket did not have anyway near enough contacts to do that. On older amps, when unplugged the socket shorts to pins connected to the speakers. Once plugged in the now broken contact touches the earphone plug and diverts the sound to the headphones. I expect the inside of the headphone socket is used to remove or supply a voltage to the mute pin on the IC, either directly or via and inverting semiconductor. Unluckily for you the corrosion was doing the same job.
Spoiler Saver
I know these spoiler savers rarely work, but here it is anyway. I hope you enjoyed this one 👍
My bad - will remind myself to not post until it has gone live lol! I just can't help it!!!
I like your rad Matt
can you show us how to replace a screen on a game gear?
I thought "headphone socket" the instant you switched the unit on. But corrosion hidden by the socket isn't something that I'd have thought about immediately, so you are forgiven. I'd add that in my experience of repairing similar equipment, the audio chip usually fails catastrophically with a burn mark or visible hole.
You need a signal tracer. That would have sorted this out quick. Power it up open and trace the audio path till it turns up dead. I FIND YOU! Rotten little gremlin. And gitter fixed. No more KNACKERS. Also Pro Tip, use lead solder... Its good for your brain and the environment and no TIN WHISKERS. Also you don't need to clean up the flux so completely. Just wipe it with an alcohol wipe if there is excess. Lots of boards out there with tons of flux on them. All works good. Save your time. You are not someone elses maid.
A tip: the Amp chip got power and audio in but no audio out. That could either mean it is broken (as you thought) or that it was told to not output the audio. With the data sheet you would have been able to test it. The chip is quite simple. There is the mute and the standby input. Either of those will be enabled from the board or another chip when you plug the headphone in. So you could have measured that on those pins before you replaced the chip. So what I am saying is take one more look at the data sheet. That being said: great fix and it is totaly understandable that you thought it was the audio chip. Thought so too until I saw the remaining time.
Thanks Daniel, maybe this is where a scope could have been used on those pins to see if I could see the signal switch high or low when the headphones were plugged in 👍👍👍
@@Mymatevince The signals would probably not have changed because the device thought the headphones were always connected due to the corrosion.
Ok no point watching the video now😢
@@Mymatevinceyou kept mentioning mute but never checked the mute pin i really thought you where going to have it. I only had some prcognition to the issue because I have used tpa chips before, you don't need a scope the mute/standby pins are high low signaling so a test with the dmm would work. (Pin high or low and refrence the data sheet to see what high and low is.) I probably would has assumed a fault in the mute circuit and just removed it or installed a manual mute. Also my fault finding skills aren't up to your level, Although a mute circuit is needed for anti pop on startup.
P.s. in some places when you just need to check if there is an analog signal and not know the what the siginal is you can just mesure the ac voltage. Line level audio is ~2v headphones are anywhere from 0-2v on most devices.
@@Марк.Фетновwhy are you reading the comments before watching the video🤦♂️
Everybody needs a mate like Vince.
Or Northridge fix
My friend. I have been an audiophile for forty years and I watched your video with great interest and zero understanding whatsoever. Your fluency in electronic engineering is masterfull. I heard every word you spoke but the meaning utterly escaped me. I feel such a dunce. Huge respect to you, however, because i watched your video all the way through just so that it sank in just how stupid I really am.
One thing you should consider buying is an oscilloscope, you can then use to confirm audio signals from the output of the amplifier chip, follow the traces round and see where the audio signals are lost. You can also use it to check the audio signal waves are correct using the diagrams often found in service manuals, as well as using for things like tape deck calibration, head alignment and all sort so of other checks very useful for electronics repair.
Absolutely. USB powered oscilloscope front ends that use a PC display to show the waveforms are pretty cheap nowadays.
@@rogerphelps9939You can even get an inexpensive one that plugs into the USB or lightning port on a smartphone or tablet, and uses that device's display and touch screen to control the 'scope.
@@rogerphelps9939 - I used to fix a lot of radios and he should have a signal tracer. Better than a scope because it can indicate data or actual audio or some other signal. And invaluable tool
I must admit i was shouting at the screen at the very start " get a jack in the socket and give it a wiggle" you wouldn't believe how common it is lol, you got there in the end but always the first thing i do with " no sound" faults 😊
Anyone fixing electronics for more use and extended life is a hero!
The signal from the jack goes to the Mute pin on the chip to mute the speaker out and play only out the phones.This is not the same as what the mute button does on the remote. I was yelling at the screen the whole time :-)))) Love your enthusiasm, it is contagious!
I was literally screaming at the screen as soon as you dismissed the jack at the beginning.
I didn't feel that you had tested that properly in the first place. The identical jack beside it was the perfect reference to thorough testing.
Hi Vince, it is so so nice to see your genuine joy from being able to fix something. It made me smile. That joyfulness is infectious, in a good way! Thank you!
Thanks Marcel👍👍👍
Love the "YEEEEEEES" lol! A fun watch, it's frustrating when you miss the obvious - we've all done it!!!! You've covered two repairs in one really, because there will be units of that out there where there's no sound at all, and it will be that amp IC probably!
Thanks Chris, it has been a while since a YEEEEESSSS has been unleashed. Very happy with this one 👍
I could watch Vince do honest repairs like this all day. Great stuff.
Great job on the repair. You've given me the incentive to repair the home cinema remote control that had a battery that decided to leak and stop it working. Replacements are only available in the USA or China for £30 for my specific make. It is back up and running after white vinegar and IPA. I did desolder and resolder the components around the problem to ensure a deep clean of everything - yes, the desoldering gun (that I got after winning some money) is a game changer.
Thank you for doing this video. I actually work for Bose tech support and deal with these all the time. It's nice to have an actual look inside and get an understanding of what goes on in the repair centre 👍
I'm also right at the start of my electronics learning curve, so watching these vids really helps get to grips with what everything does. I've learnt a lot from vids like this ❤
False starts are always a good learning experience, frustrating at the time but always a memorable lesson. The most valuable experience I got out of my uni electronics laboratory class was that connectors and cables are your enemy - nothing like spending 90 minutes tearing apart a circuit, swapping out instruments, etc. only to find that the actual fault was a worn cheap cable between the oscilloscope and the circuit. Videos like yours show how much abuse cables and connectors take and how vulnerable they are to mechanical and chemical (corrosion) damage. Add in the failure rates of MOSFETs and ceramic SMD capacitors and it's amazing how much dead gear is easily recoverable.
Well done!
You are understandably wary of high voltages around mains inputs. Don't forget that you can power a unit like this using your bench power supply instead while testing.
This might be one of the most satisfying fixes you've ever done. Never seen you so happy.
I was "I hate to say I told you so, but I told you so...". Immediately suspected the switching function on the jack, instead of the amp IC. Usually mechanical components fail before electronics... Glad you fixed it in the end and it wasn't a 100 € part. At least you've got a spare now ;-)
Having fixed many of these style Bose Radio CD's in the past the most common failure is those silver SMD electrolytic caps. They leak and cause various issues including No Sound, CD Not Reading, CD Not ejecting/loading, burned amp chip and i'm sure other strange issues which I have yet to come across. If you truly want this to be reliable a replacement of these caps is a must!
last week i saw what i thought was a Bose Wave radio sitting beside a dumpster. i yelled STOP! at my brother and jumped out of the car on the side of the road and ran back to get it.... it was an under cabinet radio/CD player from someones kitchen. Not Bose... it was GE(general electric) brand. It's now an under-the-toolbench garage radio. :)
Water damage to circuit boards can be a real curse, so well done for locating it and rectifying it.
I have the same problem, and I'm so glad that you took the first step on the moon for me and I can't wait to stop watching this video so I can go run and fix mine. Man I love you lol thank thank you for showing this video. Great job 👏 👍 👌
That was beautifully done. That one could have quite easily fooled a professional... (like me).. Thank you Vince for teaching an old hand to persevere! Even though that was the very first thing I would have checked... I may have had trouble.
I remember first models of these Bose radios came out in the mid 1990s. These are not just the 2 speakers, but there are specially designed sound chambers behind these speakers that make the sound sound "bigger and spacier." I remember my engineering teacher had a diagram of these chambers on his door to his office :). It was supposed to be new tech in audio technology.
Not really. Just some mumbo jumbo to con punters into parting with their cash for something that isn't all that it is cracked up to be.
Emperor's new clothes. Just like quadrophonic Hi Fi was for people with 4 ears. It is BS I'm afraid. Big names like Bose and B&O made their fortune by feeding the Hi Fi snobs with basic stuff wrapped up in weird cabinets.
Yup is a resonant acoustic waveguide
The B&W sounds better because there is more volume inside. More space to tune the driver to a lower frequency.
@@rogerphelps9939move on, putz
I’m a huge fan of your videos. You followed a logical fault finding path, but as soon as I saw it work on headphones I expected the headphone jack based on experience. Congrats on getting it working and I’m sure that TDA chip will be useful another day, it’s a small price to play.. we all know the feeling of changing a suspect component only to find it makes no difference.
The difference with the Bose, is that you will hear it almost the same everywhere in the room. I remember the first time I played the demo disc, I was wowed, but that novelty soon wore off. But I do remember thinking that it filled the room better than other equipment I had.. All Bose products are way too bassy and that is a massive minus for me. But great job with the first guess and being proved right. Love this channel
It being bassy was the reason that it sounded the same everywhere in the room.
I like fault finding - it is the highest form of puzzle solving - true detective work. Well done, Vince.
Vince your fault finding skills are absolutely incredible. Im sure philips use that chip in there car stereo i may be wrong tho but i have i have definitely come across and replaced that chip a few times over the years but it was a long time ago i cant quite remember....i was convinced it was the ic as well
You are too kind Stacie! I think a pro would have measured the chip with a scope and noticed no difference was made when the headphones were plugged in, and worked out what was what pretty quickly. I scratched my head on this for hours upon hours 😂 Still perseverance got there in the end.
It was even advertised as a car stereo chip.
I'm 22 mins into the video. You're about to check for output from the TDA chip. I'm guessing there is none. It might be worth checking the logic level into the mute pin and also going back to the audio out jack and checking where it's sound comes from, as you know the earphones work. My guess is it's either a mute fault or a problem with the audio out socket not making contact when there are no earphones plugged into it. Right now I'm going back to the video to see if I'm right... Reached the end - well I was nearly right. The earphone socket works by resistance and mutes the main output from the sound chip. In many older items a faulty earphone socket causing no speaker sound ( the socket being open circuit when nothing is plugged in it) is a common fault. Great video. It made me laugh to see your absolute joy at fixing it. 😃
The pressure of you plugging it in and out was causing the ingress to shift, that's why it worked briefly when unplugging the headphones! Liquid ingress is a tricky beast! Just like bad grounds! Great job!
At least you’re finding plenty of uses for your expensive Kapton polyimide tape! Good stuff! Many other channels leave out the prodding about with the probes but that leaves out the beginner / intermediate level knowledge that surely everyone needs to attain sometime. So you’ve made this one a very comprehensive job! Accolades, friend! Haters will always hate, but you’ve made this so valuable to those of us who need to learn from it!!
…and you’ve captured the very moment when you realized your accomplishment! That excitement is the stuff of a good life of value with achievements!
We learn from you. The suppliers mimimum order costs always wind me up when they have the most sophistocated logistics available. CPC used to have a trade counter on North road, Preston, oh that was 40 years ago, same with Farnell in Leeds, not sure if they still have them if your lucky enough to live nearby. Fixed some skiped Kern lab scales this week, someone must have plugged wrong psu in, not 12V centre +, shorted the protection diode and was scrapped off. £900 thrown away for a component designed to protect , and it did. Pleasure to watch. Great result.
Nice work, as always, Vince! TBH, I was trying to tell you to remove the headphone jack from the pcb at the beginning of the video!
I was nearly certain that the problem was in the headphone jack. I was so flustered when you eliminated it, I skipped to the end. Relieved that you found the real problem.
Good Job Vince 👍 I had been thinking something to do with the headphone jack. The TDA chips usually fail short and get hot or blow a fuse or such. I thought the socket might be faulty, but didn't expect corrosion underneath it. Well spotted. Seems we have both did a video on Audio Equipment, and in both repairs the root the cause was corrosion! Keep up the great work. Best wishes Mick.
Thank you Mick 👍
@@Mymatevince Pleasure sir 🙂👍
If there are cooling vents on the top check for corrosion, that's where the water, gin & tonic, beer, coffee and tea tends to go.
A lot of these Bose units were used as bedside radios and a simple spill with a bedtime drink in the middle of the night will be forgotten about over the years - especially when handed down the generations.
Vince! Perfect timing. I got one of these on my bench right now. Super bad corrosion on mine. But it's in the same area you're working on. So I'm learning today.
I've had exactly the same. I thought it was leaky SMD electrolytic capacitors but I'm wondering if the location is such that an accidentally spilled drink could concentrate around that area. I remember when I replaced the capacitors I didn't get the usual cats pee smell you get when desoldering.
As others have said, I was virtually shouting at the screen "check the mute signal!" after I had checked the datasheet quickly! I thought at first that headphone jack would be one with switch contacts - the "cheap" way of muting the speakers is to route the signals through extra contacts on the jack which are open circuited when the headphone jack is inserted. Such mechanical switching is well known to be unreliable, so would be a first assumption. However, when you showed the jack socket connections, it was obvious it was not that sort of socket. Well done for eventually finding the problem. What I can't remember seeing before is those "spark gap" traces on a headphone circuit. I would not like to be wearing headphones when that spark gap flashed over - with that sort of gap it would probably be several hundred volts!
Great Channel!
Vince, if you replace Parts mounted on Heatsink think about mounting them first before you solder them!
That will reduce Stress on the Part and prevent from cracking solder Points.
Also bend Legs if straighr mounted to give some Relief when getting warm/cold,....
Thank you for your great Videos!
I was actually waiting for the part where the screw wouldn't go in but I think he got lucky on this occasion. I've seen some real "engineer" bodges in the past where this happened and whoever did the job just left the screw out and the IC without any heatsink contact at all.
Great fix and experience. I really thought at the beginning you would remove the earphones jack, then we wouldn't enjoy all the tests and findings 😊 awesome video as always MMV!
Great fix sir. Well worth remembering your approach and the added advice in comments.
i repaired a lot of these back in the days... I worked in a Hotel with 250 of these things in it. I love the sound and most of the time the guests ripped something out of em.
I feel your joy :) Awesome troubleshooting. And a lesson learned about buzzing "shorts" or ohming out the real way
Great result, I've overlooked the simple fault and have pulled things completely apart many times, I feel such a twat spending hours only to find it should have been a 10 minute repair
FYI, TRS jack Tip Ring Shield, Tip = Left, Ring = Right and Shield = Ground. Thanks for the informative content you always provide. 👍
I have always heard the "S" called the "Sleeve". Not in all cases is it used for a shielding conductor.
I watched this one last night and I was thinking- why doesn't he use a signal generator, injector etc- which would have proved the TDA chip but then when it was tested and didn't work, I had to admit- a signal gen wouldn't have found that fault! Well done, that was edge of seat stuff in the end!
I think the "mute" pin was the key here. A check on the datasheet would show whether it gets pulled high or low to disable the output. A quick check with the meter there would have probably revealed all.
Nice find. Excellent repair. Not easy to measure at all.
Feels good to know I'm not the only one who manages to knock over the little caps of ipa no matter where I put them.
I have no idea about electronics, but I found this strangely satisfying!! And I cheered when it worked!
You had it right from the start it's always the places you don't see causing an issue when liquid damage is involved great fix vince need one for yourself now 😅
Cheers Chris👍👍
Great video. I had a hunch that it might be the audio jack since the chip was getting power and didn’t seem to get hot (based on no voltage drop at the input). Enjoyed this video (and your other repair videos)!
I cheered along when I heard the sound coming from the speaker! Great video and love your style.
Great job My Mate VINCE! I do like the red mat I grew up on Weller that is what my father had. I keep my 90% in a small 2oz spray bottle good for projects great for old guys like me with wobbly hands 🙂, have a nice day!
Good news, the red mat isn't an eye sore. As for the audio issue, glad you got it sorted though sad you missed such a basic clue. Sound quality though, Bose "No highs, No Lows. Must be Bose"
A lot of this type of repair relies on experience and familiarity. I came across a very similar problem involving a TDA dual amp chip in studio PPM and monitoring set. In just the same way the unit worked through headphone, but would not work through the built in speaker. I have learnt that before removing a chip if possible it's always worth checking all the pins for their operation. In my case I found the lack of speaker output was due to the standby pin being active, which was controlled by a contact in the headphone socket, which wasn't closing when the jack plug was pulled out.
There was also another problem with mine, and its something that has happened on three separate items of 1990's equipement, and that has been SMD resistors values drifting very high. Worth bearing in mind.
I’ve got an older model one of these that I found at the ewaste pile at the dump .. I love it . Sounds amazing.
I own a B&W and still a great piece of kit that also looks good , mine did have a well known buzzing sound and then the sound died, sent it off to B&W and fixed it for £80 and that included posting what a fantastic company to be able to fix it at that price not many will do that. I think the problem was a capacitor blew a well known problem. That Bose is such a classic remember those from growing up and wanting one.
Bose are a pretty lousy company on the whole, do some reading of their wikipedia entry.
@@6581punk I’m more of a b&w fanboy own zeppelin a Z2 ( a brilliant little speaker ) and 2 style of headphones on your ear and in your ear and love the sound setup by B&W
I had one with loud buzzing and found bad corrosion all round the IC and a crack in the IC front. I thought it was from leaky SMD electrolytics around the chip and replaced them at the same time, but I actually think the owner wasn't honest and had actually spilt beer inside.
@@michaelmcdonald2348 yeah sounds like a spilt drink issue
Bose - OVerpriced, overrated @@6581punk
When we get a product back for repair at work, the first thing we do is inspect the board. We've seen all kinds of corrosion, some I can't even explain. My favorite was when water dripped int he unit through concrete for several years. Ate so much of the copper off the board....So on a jack like that, instead of breaking the audio lines, it generates a logic level output to signal if something is plugged in. Usually these are high impedance lines (compared to the audio signals and might use a 10K or even 100K pill-up resistor, or perhaps a weak current source internal to the chip it is driving. With a 10K pull up resistor, even something on the order of 5K resistance from the corrosion might be enough to cause the problem you found.
One other thing to look out for and tuck into memory. If someone else worked on something and used water soluble solder and failed to clean it, the same problem can occur but is even less visible. Cleaning water soluble solder with IPA can be as bad as not doing anything with it, it must be cleaned with water first. I've seen this four or five times now. In fact, the one switching regulator I use in designs will not function properly until the water soluble solder is totally cleaned off. I mention all of this because it can be a very difficult problem to troubleshoot.
I enjoyed the video. Keep fixing more things and add to your knowledge base. I also agree with the post about getting an oscilloscope. simple 2 channel digital scopes are dirt cheap these days and surprisingly decent. I have a $350 four channel Rogol at home and it has impressed me for the cost. It even does a few things better than my Tek. Also, I would recommend an isolation transformer. It can save you and especially a scape which normally is grounded to earth ground. Above all, have fun and be safe. I 100% agree with covering the mains voltage like you did, just in case, especially with 240VAC.
Great video. I would also have thought it's the chip :D
Thanks to your old video I've also saved an old Zeppelin recently and I love it. The seller said that the manufacturer doesn't have spare parts for them anymore and since they just swap parts instead of doing real repairs, like most manufacturers, there should be many around these days to rescue :)
When it comes to order some extra chips to get a better value out of the high handling and shipping fees:
I had to replace the Injoinic IP5306 recently a few times so they might be something worth to have spares from. They're pretty cheap, but common in battery powered electronics from China. I had them often in LED lanterns with USB-C charging. It's a 1S Lipo Charging chip that can also create a 5V 2A Output and display the battery capacity. Especially when people try to plug a micro usb cable into the USB-C port or short the contacts they sometimes fail.
Such a sneaky fault wow, the signs really threw me for a loop too. Fantastic fix Vince👍
And don't forget to do a visual inspection of the board and components always first. But maybe you do but cut it out of the video
I stopped watching the new version of Kitchen Nightmares for this. I made a wise choice.
You put us through a rollar coaster but I love a success story, great video and will subscribe. So great how you ventured on.
I spent a fascinating hour watching that ,who would believe it Brillian Video it was like being in your workshop
Thank you Bill👍👍
Great fix Vince, but more importantly loving the red mat!! :)
These things are expensive for a reason as they deliver good power and 'fill' the room with sound. Well done for perservering with it and maybe next time go with your first gut instinct. 😁👍
Cheap plastic tat. With the speakers so close together you will not get a good stereo image unless you sit right in front of and close to it.
@@rogerphelps9939 Hardly cheap!
Brilliant as always. You have inspired me to try and fix my own things.
Around a third of the way into this video I found myself yelling at the TV, screaming "No, no, no!". I think the neighbors may have heard me. 😆 Why was I reacting that way? Well, aside from my obvious emotional issue, you had ignored the contradictory fact that the headphones were working when you diagnosed a failed audio amplifier chip. In order for the headphones to work but the amplifier chip to have failed, there would have had to have been another stereo amplifier chip or a pair of op amps in the circuit, powering the headphones. But we knew there were no such components. If you had access to a schematic, I'm sure you would have noticed that the power amplifier chip you replaced did in fact feed the headphone jack, which would have instantly ruled out that chip as the problem just a few moments into the diagnosis. Oh well, live and learn -- and your video was informative as you worked your way through. Glad to see the Bose finally working in the end.
You are the best and we all are learning from you.
Excellent job on diagnostic and repair always appreciate the videos thanks for sharing.
Excellent repair Vince. I was cinvinced it was the TDA chip too. But corrosion under the headphone jack? Wow
I thought it was the caps that feed the audio to the main IC, as I've had a few Bose audio goodies from the 1990s with dried out or shorted caps. Alas corrosion shorting the mute, even easier fix😂
Bose wave technology is in the black box that holds the speakers, it is multi curved like a wave to enable bass port exit out the back of the unit, so when put up against a wall it generates more bass reflex. Smart design and it goes back to the V1 model.
Not really. Cheap plastic tat.
@@rogerphelps9939 everyone is entitled to an opinion.....
Mine is based on the facts.@@stevewaller6577
Another good video.
For the Isopropyl try needle tip applicator bottles, knock them over and they don't spill.
Great that you worked it out. It's always worth cheeking the mute on the audio ic. Looking at what you were doing it was clear that the headphone socket has some basic switch function that activates the mute function on the main audio amp ic. I think the headphones are feed from another ic. But nice another piece of equipment saved from landfill. 👍
Learnt a lot from you Vince Thank you buddy and well done on this project
I'd be wary of using pc heatsink paste, for example MX4000 as these contain silver particles that can short out an audio transistor if the can of the transistor shouldn't be connected the heatsink electrically. Also it can short out the pins on the chip if used over zealously. Just use regular silicone based white paste.
You won't find the former heatsink paste in any audio consumer electronics.
You could then be in the same situation where your multimeter doesnt show a short on continuity but still a short on ohms reading.
Aww yes!!! :D What a great fix!! And you have some spares for a next project. Hahah. 😅 I think that chip is quite common in audio products, i hope you find a project to have it used!!
Fingers crossed 👍👍👍👍 Cheers devtty
44:44 as you said, you're not an audio guy, but you may be interested to hear that amongst some audio guys, BOSE is considered an acronym for "Buy Other Sound Equipment". Make of that what you will! 😂 Awesome video, as always, and a great fix, too. Great job, Vince.
addicted to this youtube channel
Good job of fault tracing.
I've had enough problems like this on my own equipment over the years, usually with the 4th contact that signals connection, that the first thing I'd suspect is the jack socket.
Knowing there had been water ingress, the first thing I'd have done is desoldered the headphone jack, as you did.
Also a quick check I'd try would have been to desolder jacks, compare them and then swap them.
I know one's input and the other output, but I'd bet they were the same just to keep parts inventory simpler.
Yes, wherever you have board mounted components like that there's a gap for capillary action to trap water and promote corrosion. With my eyesight I might have missed that. Mind you I'd also have been signal tracing with my oscilloscope.
On cheaper systems the contacts will oxidise with age, so I'd have tried Deoxit too.
I am surprised the contacts aren't gold flashed, Bose is expensive enough !
My next project is a laptop in a nursing home that's had plenty of water and tea spilled on it, plus the power lead pulled to the point the plug is bent. I might get lucky and fix it ;) If not it's spares.
Hi Vince, Great work you've done. That something so simple can (eventually) lead you so far away from the real problem. You handled it well by not first measuring the entire device, which would take hours. Looking forward to your next video! Greetings Marcel
your first inclination was the right one Kudos!
great Vince i thought for a moment you had failed, but you are a great fault finder
I bought a older version on eBay as not working. The cd drive had failed and wouldn't load . It was a horrible yellowed with age cream and I got it very very cheap. After watching a few videos of taking the. Whole thing apart I started on mine. Lid off was pretty simple and it was then I discovered the cd fault. The previous owner had tried to load 2 CDs. Maybe they had stuck together, maybe they hadn't realised there was already one in there, But, with a pair of long nose pliers I pulled the disks out ad it worked perfectly. The shell I scrubbed with sugar soap, masked the screen and cd slot, and sprayed it Matt black.
Three years on and it's still quite happy.
Well done Vince for another great fix, love this video!😊
NGL, I suspected it was the jack as you have had something similar a few months ago, although that was a jack fault and not an under the jack fault lol. Good fix Vince
Thanks Emma 👍
Great repair, Vince. I’m loving your new red mat, by the way!
Thanks Chris👍👍
My first thought was to take the Jack out then give it a whirl to see if it would work, but we are all experts after the event 👍
Well done interesting video, I use a small pump bottle for my IPA ( it used to have glasses cleaner in it)
What a sneaky one! I really love how happy you are screaming yyyyyyyyyyeeesssssss!!!
Vince....he went from Mr Telephone to Mr Audio, that Bose should compliment the Zepplin and the QUAD perfectly!
A perfect watch on a Friday afternoon. Cheers Vince!!
You should have check the mute pin and compare with data sheet for the IC.Maybe it was muted by that corosion .the check for the mute with the remote control was irelevant.Big like for your videos.
Absolutely love the reaction, haha! Brilliant result!
The celebration at the end was brilliant. Well done for fixing it. Hope you made some ££
I have the same issues with IPA. Ended up using some of those small spray bottles. Can spray onto the surface you are working on or the cotton bud or brush. Slightly more hassle but never spilt any since.
In my experience in fixing things like this, it is not normally the amplifier chip but some other reason like an earthing fault or resistance on the mute input, etc so I was not surprised when your chip replacement did not work. Been there done that.
I hope your mate is happy!
I like the red mat it contrasts nicely with the electronics.
That Extended "Yes" with the fists towards the end earned you a Like LOL Great Job Vince as always!
I was screaming measure the standby/mute voltages on the chip. In some audio amplifiers it’s quite normal to switch the audio using the headphones to either the speakers or the headphones via a suitable reducing resistor. But your socket did not have anyway near enough contacts to do that. On older amps, when unplugged the socket shorts to pins connected to the speakers. Once plugged in the now broken contact touches the earphone plug and diverts the sound to the headphones.
I expect the inside of the headphone socket is used to remove or supply a voltage to the mute pin on the IC, either directly or via and inverting semiconductor. Unluckily for you the corrosion was doing the same job.
Thanks for the info Digi👍👍