Repair of M-Audio Studiophile AV 40 Speakers
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- Опубліковано 10 лип 2024
- In this video I investigate a failure in the internal electronics (the power supply section) of the M-Audio Studiophile AV 40 Speakers.
Watch it until the end to find out what was the faulty component and what caused an additional damage which normally shouldn't occur.
- Repair of M-Audio Studiophile AV 40 Speakers
- Reparatur der Lautsprecher M-Audio Studiophile AV 40
- Поправка на звучници M-Audio Studiophile AV 40
(General subject: How to diagnose and track down a fault in electronics / Electronics repair tutorial)
Music:
Seeger - John Deley and the 41 Players
Forever Believe - Audionautix
Deep Hat - Vibe Tracks
Golden - Vibe Tracks
Rollin Back - MK2
Shoulder Closures - Gunnar Olsen
TFB9 - Vibe Tracks
You Like It - Vibe Tracks
Foundation - Vibe Tracks
Forever Believe by Audionautix is licensed under a Creative Commons Attribution license: (creativecommons.org/licenses/...)
Artist: audionautix.com/
Copyright © 2017 Goran Dzambazov / Горан Џамбазов
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Any unauthorized copying, re-uploading, modification, alteration, editing and distribution of this material or parts of it is prohibited, unless expressly authorized by the copyright owner.
Please ask for written authorization / permission if you are interested to include parts of this video to your project. - Наука та технологія
Very very well done!It was educative,practical, detailed,excellent video quality and angles as well the explanation is just clear!I think that I never seen such a good repair tutorial ever before!
Just go on!
Thank you very much for your wonderful comment!
@@GoranDzambazov I have here a Edifier R1700BT PCB,which has no output to the bass driver.Would you take a look at it?It could be maybe a new tutorial video from you ;-)
Do you live in Germany?
@@zsoltsu I'm curious to take a look at it. However, as I live outside EU, sending the board to me and then returning it to you would create some logistical difficulties.
This is the type of repair video I like to see! Great FA steps and root cause, and descriptions of the approach the whole time. AwesomE!
Thank you!
In my case the hum sound came strictly from 2 sets of capacitors. I replaced those tonight and now my My Av40 monitors are working again for the first time in 2 years. I replaced these CAPACITORS : (2) 220uf 25v and (2) 3300U/35V. I found a deal on Amazon and was able to buy 100 capacitors for only $8 which was cheaper than just buying what I needed. If you decided to do this yourself, expect to take about 2 hours, disconnecting a reconnecting the speaker to motherboard wire is a Pain. ( Unless you are smart, like Goran and disconnect at the board..facepalm) Excellent video, it's too bad I didn't find this video before I began. No doubt, I could have saved a lot of time and a headache. Regardless, my studio monitors are working again. Thank you.
Thank you for the feedback and for sharing your experience.
Hi Goran,
Thank you for your very good exploration of the problem and finding its solution. I appreciate your intelligence and thoughtful thoroughness. I, also, had an overheating problem with my AV40 eft speaker and read a tip from a guy who detected direct contact between the transformer case and the speaker magnet, which produced a short, who then suggested putting a plastic shield between the two. I did so and the overheating problem went away. In another video a capacitor also was to blame but was different from the one you found.
Thank you very much Jon for your comment.
Do your speakers now work normally?
Goran you made an excellent video guide and explain basic troubleshooting methods. I like to see you are not confused with uncertainty measurements especially resistance in the circuitry. I repaired mine AV40 before few years and found an electrolytic capacitor was vented out so after replacing all power supply capacitors humble noise was gone. Recently channel on the main box was gone and another channel had a hum noise so it will be fun to repair. I suspect the problem may be caused by TDA7265. By the way, I recognize the Unior pliers you used, I got the same tool to bring with me a long time ago. Keep doing educational work and stay safe!
Nenad, thank you very much for your comment and feedback and for sharing your experience with us here!
Yes, the good old Unior tools were especially appreciated in this region and they still have a special place on my bench :-).
That was an amazing video Goran, thanks!
Thank you for the feedback!
I like my AV 40's too much to not fix this hum. Thanks to your video, I'm going to try. Really great video. Thanks for sharing it.
Thank you for your comment.
If you just experience constant low level hum from your speakers but otherwise they still work normally, then the cause in your case should be something different.
@@GoranDzambazov It ended up being a leaky capacitor. I'm pretty bad at soldering and I managed to partially detach the soldering pad, but I still fixed it. Thank you for the help.
@@EricHaluska Great! Thank you for sharing your experience with us.
Finally i found this same problem with solution my studiophile, thank bto.
Interesting… I'm getting a very similar issue with mine. I get the loud hum like yours (it seems like it goes in and out of phase at the start and then just stays "in phase") but I still get sound from both speakers… except very distorted! From your video, I suspect it's the amplifier and, while I'm willing to give a shot at the repair, I'm not sure it's worth the cost of fixing them… 😬
Thanks for the extremely detailed video! Regardless of whether or not I got ahead with the repair, I enjoyed your walkthrough and strategy to pinpoint and fix the problem! Pretty much an electronics lesson… :) Kudos
Thank you! Comments like yours motivate me to continue with my electronics and repair video lessons.
Thank you for this amazing video! I learned a lot.
Thank you for the feedback!
Very interesting video. I got here looking for a way how to remove the front grill, but watched it all. I checked my fuse, luckily it's the good one. ;-) Thanks for sharing a great video.
Thank you!
awesome video, very informative. thank you very much
Thank you for the feedback!
Sir, that was satisfying to watch.
Thank you.
A very detailed and informative video.
I had a similar problem with my Mackie CR4 monitors. When turned on, they would silently crackle intermittently. Turning the volume knob made no difference to the crackling level. Both speakers produced audio, but the crackling was annoying.
The CR4 build is quite similar to this one. The powered speaker had a diode corroded and broken in half. The caps looked OK. I replaced the diode snd the crackle went away, for now. Hopefully that was all it took. :-)
Greetings from Serbia.
Thank you! / Hvala!
Very detailed and informative video. Thanks for this.
So... I will just go get another pair of studio monitors. I don't have the skill or the tools to do what you just did.
Thank you for the feedback!
From your comment, I assume that you have the same or a similar problem with these speakers. My case was a bit special though and there is a possibility that in your case there is less damage or that the cause of the problem is something else. So if not you, then perhaps same skilled electronics technician can help you fix them.
Excellent presentation. Great methodical display of troubleshooting.
Thank you!
@@GoranDzambazov You're welcome. It's just the truth. I used to work at a bench repairing a specific model of amp. Your presentation really can show other techs a methodical, well thought out, approach. Good job !! PS: if you want to hear some of my homemade jazz, mixed on these AV40s Check out this website. These are unmastered songs (kind of basement tapes, style), and are one man band stuff. kenteel.bandcamp.com/releases
@@GoranDzambazov Goran, here another homemade jazz song, that I think displays a clarity, that was mixed on the AV40. ua-cam.com/video/ii2J0i8BCy4/v-deo.html
@@KenTeel Thank you! I'll check it tomorrow morning.
@@GoranDzambazov Goran here is another tune Recorded and mixed on the AV40 speakers. ua-cam.com/video/tUMieGC32-0/v-deo.html
What a beautifully produced video! I have no sound from my left speaker (the one with the amp in it). I would love to try repairing it but I don't have the tools or the skill, and I doubt I could easily get the required components here in Bangkok. I have had 10 years' service from these speakers. I think it's time to get my credit card out!
Thank you, I'm glad that you liked the video and I hope that the new speakers will work even longer.
I have the same problem with my speakers and I've got most of the tools and (used to) have the skill... so I will see if I can get my problem resolved. If you still have your speakers, see this link (projects.g.ydftech.com/home-1/m-audio-av-40) for a detailed explanation for the possible issues with this speaker.
@@brettwertz7069 that link no longer works - has it been replaced or is the site no more?
They was an extra fuse in the box so I'm good ..thanks again
Great stuff.
Thank you.
Hello, does you know what is the black seal that use to seal connector, in back plate, does it glue or some resin?
You’re a genius!
I got a name for you
“E-lectro-G”
Thank you! And I like the name!
Well done. Trying to troubleshoot my own AV40s which no longer turn on. I suspect a similar problem to yours. However mine look a little different on the inside (newer model?) and various parts are glued together, making it difficult.
Thank you.
If you haven't done that already, you may first check the fuse and replace it if it's blown. Sometimes it can be that simple. However, there are often other failed components, so, before you plug in the speakers back to the mains power, you'll probably need to continue investigating further and verify that everything else is OK.
this guy has a lightning rod on top of his house just to make sure he gets a chance to work on his electronics
I'm honoured by this unique compliment! Thank you! 🙂
I have AV30 speakers that have the humming noise and make the popping sound when switched on. The volume switch also crackles when moved. I opened them up to have a look today and 4 of my capacitors are bulging with brown stuff coming out of them so I’m guessing that is my problem? You make it look so easy to remove and re solder things but not sure I can do it myself. Great video anyway, very detailed!
Thank you!
In case if you still decide to do the repair yourself: Did the humming sound develop progressively over time or it started abruptly? It's very likely that it is a result of bad capacitors (and bulging is an indicator for that). And as you say, if there is a brown stuff coming out from the top vents then the things went too far - in that case they definitely need replacement.
Otherwise, cleaning the volume potentiometer should resolve the crackling sound.
Goran Dzambazov thanks for your reply. I bit the bullet and did my repairs, bought a soldering iron, solder, the replacement capacitors, and some contact cleaner. I replaced the 2 large capacitors and the 2 small ones and cleaned the knob with contact cleaner. My volume now works better, no crackles and it’s even through both speakers but I still have a very low hum/buzz and popping when switching them on/off, any idea what other component could be causing the issue?
I'm not sure if I can give you a clear short answer regarding the popping sound for these speakers. Mine do the same and I believe it was so since the beginning (however, I'm not their first owner). In short: The amplifier IC used in AV40 is TDA7265 and in the manufacturer's specs it is clearly stated: No pop at turn-on/off. However, I did not investigate/examine if M-Audio followed the typical application circuit given in the specs in their design neither I tried to fix this problem yet.
You say that the hum volume is now very low and I assume it is a result of the capacitor replacement. At this point I would still check the ripple voltage level of the DC supply voltages with an oscilloscope during operation to see if that can be the cause of the hum.
This is EXACT what I've been looking for! My symptoms are definitely not the same but you've answered a few questions that I've had from a disassembly perspective. Also, for people who have come here for the same reason I have (audio issues with their AV-40), there is a really good write up on some potential issues with this speaker here: projects.g.ydftech.com/home-1/m-audio-av-40. Thanks Goran for such an great video!!
Thank you Brett.
@@GoranDzambazov Since something on my main board has issues, would it be possible to just use the crossover on the main board so that I can externally amplify the speakers? If so, how would I go about finding the crossover components?
@@brettwertz7069, the IC amplifier used in these speakers is TDA7265. The signal outputs are the pins 4 and 2. You can find and study the datasheet of this IC for better undersanding of the circuit.
Hello! Thank you for the detailed repair instructions. I have the same pair of speakers, bought second hand of course because they were very cheap, but that is/was for a reason. My speakers play sound but still have the same hum and they appear to distort sound on higher volume specially if the Bass Boost is on. Any idea of what might cause that ? Should i follow the steps presented by you at least to check if the values are "normal" ? Regards!
Hi,
From what you are describing, I would advise you to check the electrolytic capacitors in the power supply section.
Hi, thanks for sharing. Can you say me where did you bought the equivalent power transformer? Does the transformer make electric noise in audio signal? Thanks a lot.
I bought the transformer from a local electronic parts store (here in Skopje). Regarding the noise, I think that now the hum level is a bit higher than before.
@@GoranDzambazov thanks for the quick response. Have a nice day.
I purchased a budget set of speakers a couple of months ago, the Edifier R2730db (2.0).
These are the first actual speakers I purchased, so I am not very knowledged when it comes to the technical aspect.
In general, I am very pleased with them, considering their price!
However, I do notice a little issue that bothers me. I am not quite sure whether this is a normal, or whether there is an actual problem here (and if so, can it be fixed? perhaps I did something wrong).
When the speakers are on, but nothing is playing, I can hear a pretty noticeable sort of noise coming from the speakers. It sounds pretty much like static noise, just a lot of buzzing really, somewhat comparable to a condenser microphone that produces a lot of self-noise.
This happens on all connection types I have tested; bluetooth and the two line ins (CD-player or USB audio interface).
When you turn up the volume, it gets worse, of course. When you turn the volume up completely, it is pretty bad and impossible to listen to. But even when I watch a UA-cam video on my computer connected to the speakers via bluetooth or a USB audio interface, at what I consider a normal volume level (it might even be on the lower side, as I cannot stand loud sounds), I can still often hear the noise through the other sounds that are playing.
Hi,
The noise issue you described does not seem normal, however, it would be difficult to assist you in isolating the cause of the problem without too much involvement.
Perhaps if you can make a video recording of what you described, so we can hear the noise and get a better overview, then either I or someone else could give you some suggestion.
Best,
Goran
Hello, could you please tell me where the black wire that is attached to the speaker's wood should be connected? I accidentally detached it, thanks for your help
Which wire exactly are you referring to? If it appears in the video, please send me a timestamp.
Hey do you think the AV42 / 32 series has solved this problem? Their website says they switch on / off automatically if they get too much signal and they have heat protection - or will they just sound crappy and then fail?
The problem described in the video is not something inherent to these speakers (AV40) but rather universal. The overheating was a result of a complex chain of events and it can happen to any electronic device. If you have omitted that part, please watch the end of the video again to see the main reason why the things developed this way in this case.
@@GoranDzambazov thanks! grabbed some av32's at best buy, will play with them today
Hi great video i have a set of AV40s i have no sound in the right side
is this the same fault that you experienced
If you watched the video carefully, in my case there was a hum and no sound from the both speakers.
So for your case if there is no sound from the right speaker, but the left one is still working normally, the fault is something different.
However if there is no sound from both of the speakers and the blue power indicator is off (with the power present), then check the fuse on the back plate and replace it if it's blown.
Hi. Do you have any suggestions on how to get a fuse out, that is partially stuck? The fuse blew and half of it is now inside the speaker. :)
Sorry to hear that. I don't have any particular suggestion. If it's definitely not possible to be removed, perhaps you'll have to consider replacing the fuse holder.
Buy an ESR meter. Allows checking caps in circuit. Nice repair.
Hi,
While having an ESR meter is useful for many other faults, in this case there would not have been any benefit of it because the fault was a short circuit in the negative supply branch. Also, most of the general purpose ESR meters have only the capability to measure the equivalent series resistance (ESR) of a capacitor but not its capacitance. So, if you attempt to measure an ESR of a capacitor (or a group of capacitors in parallel), a faulty short-circuited capacitor will incorrectly be identified by an ESR meter as having ideally low ESR (zero Ohms).
And when there is a short circuit in a group of elements connected in parallel, if there is no visual clue which one of them is causing the short, there is no other easy way to determine which one of those capacitors is actually shorting the circuit than to desolder each element and test it separately for its functionality.
Best, Goran
@@GoranDzambazov 10-4. I have a DER EE DE-5000 which provides more than just ESR. It is just another tool that can be used wrong or can hasten the repair process. Are you saying that an ESR meter across the 4700uF cap you removed to test, wouldn't have found that it was ok? I was surprised your MAudios lost the transformer. Always nice when you can fix something & not toss it into the landfill.
Measuring an ESR or a capacitance of a capacitor in circuit (as you implied in your first comment) where there is a short circuit across it because of another faulty component connected in parallel with that capacitor would give 0 Ohms for the ESR and an indefinite (OL) value for its capacitance. In that case one can only measure its capacitance or the ESR by removing it outside the circuit. So in my case, an ESR meter would not have found that the 4700uF capacitor is OK, had I done the measurement in circuit.
Your tool looks more advanced than many other ESR meters, so it might have the functionality to identify that for a combination of 0 Ohms of ESR and indefinite value of the capacitance there is a clear case of a short circuit, but still it cannot tell you more than that (it could not tell that the capacitor is OK). You can confirm this easily if you simulate my case by shorting the terminals of a capacitor (in circuit or outside circuit) with a piece of wire and then test it with the ESR meter.
At the end of the video I explain why my M-Audio lost its transformer. That shouldn't have happened in normal circumstances.
And yes, I always try to fix things and use that opportunity to create a repair tutorial for other enthusiasts :-). However, video recording during the repairs slows down the repairs significantly and due to time constrains I haven't recorded many of the repairs that I occasionally do.
Best, Goran
i got the maudio av 42, i was blasting music from an usb external audiocard, suddenly stopped working and the power indicator light doesnt turn on and i think it smells like its burnt , what could be? pls help
It's possible that there is a failure in the power supply section. I would start investigating there first.
Hi, Goran. Thanks, that was a very detailed repair presentation. I have Mackie CR4 speakers and they employ almost identical electronics. Many parts are actually the same, as far as I can tell by looking at your PCB. Mine developed an intermitent crackling noise at first. I replaced five small capacitors, all of which were bad and were located around the two zener diodes and two resistors included in the voltage regulation (like in your video). However, the PCB in that area is also blackened and started developing cracks. Is there a different solution for the voltage regulation other than via the resistors and zeners which obviously produce a lot of heat?
Hi and thank you again for your feedback and your comment.
I'm not sure at this moment which voltages do the zener diodes provide in the power supply section of AV40, however, in general, you can consider a solution using some of the 78xx linear voltage regulators mounted on a small heatsink instead of a zener diode and a resistor. There will still be heat produced, but it can probably be distributed differently (not to close to the board).
Best, Goran
@@GoranDzambazov, thanks so much for the kind reply. I actually saw what you suggested on a blog by a German guy who never actually explained in detail how to mount and connect the leads of all those components, so it wasn't much of a help. Mounting that daughter board on the amplifier heatsink could be feasable. But the speaker is very restricted in space and there is little where the heat can escape.
The incoming voltages are around 20-21 volts, reduced to 12V by the zeners and resistors - which in turn burned the board. :-/ Would the components you suggested generate that much heat like the zeners/resistors combo?
The solution with the 78xx/79xx linear voltage regulators that I mentioned should be a bit better with regards to the total dissipation (should generate less heat). In the regulators with a Zener-diode (due to the fact that the Zener must stay in reverse breakdown to maintain the output voltage), the Zener-diode constantly sinks current, which means that there is energy dissipated even in the case when there is no load current at all. (Actually, with no load, the dissipated energy by the resistor and the Zener is maximum). If you would like to learn more about this, do a Google search for Shunt Regulator.
Since your aim is to move away from the board the elements that generate heat, putting one 7812 (and one 7912 (I assume that there is a negative voltage as well)) on small heatsinks might help. The 78xx and 79xx are three pin regulators (they have an input, common and output terminal) and connecting them to the board should be straightforward.
Otherwise, when it comes to voltage regulation and conversion in general, the most efficient way is using switching DC/DC converters, but I usually try to avoid using them in audio circuits.
@@GoranDzambazov Thank you! I have implemented a LM7X12 daughter board in my Mackie CR4 powered speaker. The heat is now minimal, the board in that area is now just warm from the heat of the amplifier.
The electronics inside it is probably very similar to your AV40's. My CR4 monitors now work great, no sound issues and no more overheating board.
The only remaining issue is the L/R selector switch. It is covered in that black resin/glue and removing it from the part is virtually impossible without scratching or ripping the components covered by it. I guess they wanted to cover every opening to prevent the sound from escaping, but made the removal of the covered components very difficult. Any ideas on removing this black glue? Your AV40 powered speaker also features it on the inside of the back plate.
I'm glad to hear that your modification was successful!
Regarding the resin/glue, unfortunately I don't know what's the best way to remove it.
mine made the same noise like yours, I found out the 2 main caps right after the rectifier are bad, replaced the caps. No noise when I turn it on but the new caps explode again after a few minutes. What do I need to check? Thanks
Did you also check the bridge rectifier diodes before replacing the capacitors?
And also, did you observe the polarity of the capacitors and was their voltage rating correct?
I did check the rectified diod and verified the value of the caps as well as polarity. I plan to try again with another new pair of caps, will be Nichicon this time no more junk caps.
You can also check and confirm that the DC voltages across the capacitors are as expected. Good luck with the repair!
Hi, I have the same speakers, got them used, when I turn them off they make a pop/pitching noise, is it normal thing for these speakers? Thank you in advance for your reply!
A popping sound when you turn them off is usually normal but what exactly do you mean by pitching noise? Is there anything other than the pop, or, is the pop perhaps too loud?
@@GoranDzambazov, thank you for your reply! Yes, the issue is it is pretty loud, and also it is not just "normal" soft popping, but has some high pitch in it too, like chirping. Btw thank you for the great video, I did unsoldered and checked some components, like transformer, zener diodes, rectifier etc, and all seem ok, the big caps were changed earlier since it was buzzing before when I got the speakers. When I reduce the volume to zero before turning off its a bit better, but not always.
My speakers also make a soft popping sound at turn off and I believe it was so since the beginning (I'm not their first owner). However, what you mention about the additional chirping sound in your case is definitely not normal. Check if there will be any difference if you temporarily disconnect the audio signal cables.
As you probably already know, the amplifier IC used in AV40 is TDA7265 and in the manufacturer's specs it is clearly stated: No pop at turn-on/off. I did not investigate if M-Audio followed the typical application circuit given in the specs in their design neither I tried to fix this problem for me. Since you already started with the repair, you can also check the components around the mute circuit (pin 5 on TDA7265 IC). I'm sorry, but at this moment, I cannot give you any better advice.
my m-audio speakers just switched of on their own while in use
i tried to switch e'm on but the blue light doesn't glow anymore what should i do
Hi,
First, you would need to confirm that the mains voltage where the speakers are connected to is present. If that is OK, next, you would need to check the fuse: if it's blown, that might be the only failure (and you would get away just by replacing it) but it may also be an indication that there is a failure inside that needs to be investigated further.
Good luck with the repair!
Eish same here but the fuse is fine... When i check on the map nothing damaged
Hi Goran, I just sent you a message regarding the Skopje time-lapse video and using a few seconds of your footage for my project. Please check out your comments. Thanks! Andy
Great video. Thanks.
I have M-Audio M8 and the bass started to give in after 5 years, and one speaker started sparkling. Are they blown? Why would they just cave in like this? Can one fix blown speakers? What specifically has happened to blown speakers anyway? They've just been played at a moderate volume.And they've been sitting still at the same spot all years.
I assume that you are talking about sparks coming out from the woofer. That is not a good sign (regardless of which driver the sparks are coming from) and it is very likely that that speaker driver is blown. A visual inspection of the speaker and a simple check with an ohmmeter can help you determine if it's definitely out of order.
A speaker driver can be repaired, however I would suggest you to buy a new one (I suspect that the voice coil is damaged). But before you proceed with the driver replacement it is also very important to do proper troubleshooting in order to find what exactly caused the problem.
@@GoranDzambazov Thank you. No no there's no sparks anywhere. Just tried to explain the sound emitting. Sparkling,crackling,weak. The bass started to let go first, as it lacked energy, and then the rest gave in. It just seem not to want to play anymore. They don't seem blown at all in that regard. They've been sitting stagnant for 5 years with moderate playing. I suspect cheap internal parts. They just seem to have ' caved in' and don't want to give anything anymore. Lackluster sound,weak bass.
Sorry, I got it wrong. I thought that you used the word sparkling as a synonym of sparking.
An audio recording of the sound coming out of the speakers would make the things much clearer. I would check the state of the speaker diaphragm, a continuous check of the coil resistance while slowly moving the speaker diaphragm in and out, the connections to the speaker, the soldering joints on the board, the volume potentiometer, and (at least) a visual inspection of the capacitors in the audio conditioning section of the circuit (for bulging or other abnormalities).
@@GoranDzambazov Thank you so much
why not a 3.5 jack in the front audio in ?
Did you ever repair M-Audio Studiopro 3 desk top monitors?
No, I haven't repaired those speakers.
Somebody has a service manual por schematic m-audio av40, pleasse I need IT.
Hello Goran i got a speaker monitor gibbon 5 ..stopped working after i put put voltage from 230v to 110v .. now the speaker wont even turn on .its only a few weeks old .can you help me repair it
Hi! Did you check the fuse? If it is blown, replace it, put the voltage selector back to the correct position again and give it a try.
wow thank you the fuse was blown .. its working now .. thanks a million
No problem. You've had luck! :-)
But make sure also that the fuse you've put is with the correct ratings.
Did you strip out a screw head because the nut was glued? And replace the screw, that you painted at the end?
I'm trying to recall, but the repair was six years ago, and now I'm not sure what I did exactly with the original screw.
@@GoranDzambazov One screw I would like to remove is glued. I nearly stripped the head. I’m going to try to remove the glue with the soldering gun tip! I was told this speaker was buzzing quite badly but I never turned it on to listen. I just disassembled it and recapped it. The caps were obviously bulging and leaking. Well, it’s not buzzing but there is no sound output at all. The woofer and tweeter both work though, I bench tested them. The led on the volume control lights up and I have 21 volt power on both sides of the bridge rectifier. I really know nothing about electronics, just dived in to try to fix it with the help of some yt videos. I hate to be a “parts swapper” but that’s the level I’m at right now. I hope to learn electronics and be a better diagnostician soon.
@@mguerramd, I can only advise you to find the datasheet of the TDA7265 amplifier IC and continue investigating.
Check if the IC is properly powered, then connect a signal to the input and to try to trace the signal from the input to the output.
@@GoranDzambazov I don’t know what any of that means, but I’m going to find out and do it! Thanks 😊
Let’s see, check across pin 3 and pin 6 with a voltmeter while it’s in circuit?
@@mguerramd, check the voltage between the pins 3 and 9, and between the pins 6 and 9.
I accidentaly switched from 230v to 115v, i checked the fuse and the fuse is definitely messed up. Im not sure if anything else is messed up though, do you think that something else could be messed up or do i just need a new fuse?
Return the switch back to 230V, replace the fuse and try it out. I believe that the chances that it's only the fuse are good.
If it still doesn't' work, then check the transformer.
@@GoranDzambazov thanks I bought a new fuse and they are working again. But, a friend gave them to me a few days ago and he said he hasn't touched them in years. When i turn the music on, the left speaker sounds so much quieter and overall not as good as the right one quality wise. I am almost positive that it's not the wires on the outside but the speaker it self. What do you think could be an issue, and thanks for helping me once again.
Glad to hear that they are working again!
Regarding the left speaker issue: to verify that is not the source or the RCA cable from the source to the line input, try with a different source and cable or simply try temporarily swapping the cables for the left and the right channel and see if it will be the same. If the left speaker is quieter again, then the issue could be something in the input circuitry in the amplifier (in the left channel) or maybe the speaker itself.
Hello, thank you for your video. Do you have the link to the components you changed ? Thanks again for your help.
I bought the transformer, the capacitor, the bridge rectifier and the fuse in a local electronics store. Those are common components and you shouldn't have a problem finding any of them. But it's also important to correctly identify the cause of the problem.
I sent you a message on messenger.
@@tsantsatsantsa4664, if you have more questions, please put them as a comment here.
@@GoranDzambazov All right, I just bought these second-hand speakers for my son, but they don't work properly, the seller doesn't want to take them back, so I'll try to repair them. They make the same noise as on your video. I've found almost all the parts, but I can't find the transformer. Could you help me, thank you.
@@tsantsatsantsa4664, other faults could cause the same noise or hum, so you first have to properly investigate the problem, before taking an action such as the transformer replacement.
I advise you to first check the resistance of the primary coil of the transformer, the voltages on the secondary side of the transformer, the diodes of the bridge rectifier and the smoothing capacitors.
hi,i got the same speakers and the sound shutdown in intermittent way ,can you tell me how to fix it ,thanks a lot for your help
It can be many reasons. Is the blue power indicator LED on at the time when there is no sound? Did you check the cables already? Do you have enough knowledge in electronics to do repairs?
@@GoranDzambazov hi ,yes there is the blue power working normally and the cables seems ok ,well i have assembled some synth kits and sometimes i fix computers , i have found this page where they said to cut the pin 5 who is the mute on the tda7265 chip , getsatisfaction.com/m-audio/topics/av40-no-sound-but-work-for-a-few-seconds-after-power-is-turned-off , i am not really sure to do it ,what do you think
It is likely that the problem is caused by a faulty component around the pin 5 (Mute). I would try though to make a proper repair, which is to find which component is defective and replace it (or check if there are cold joints around), rather than simply cutting the pin 5 and leaving it floating. According to the TDA7265 datasheet by ST, when the pin 5 is at a potential lower than +Vs - 6V the amplifier is in Play mode. I would like to hear how this will end, in case if you proceed with the repair.
@@GoranDzambazov thanks a lot for your advices , i will check the components first ,as soon as i will finish with the fix i will tell you
Really good mine do not work at all. Like no power the blue light don’t even come on. Replaced the plug fuse. Still nothing.
Thank you and good luck with the repair!
Hi again. I have av32 that is not working. Have you fixed these before. I have 4 resistors burnt out. R13a r13b r13c r13 all in a row. But I can not read the values on to of the board.
Resistors not board. Its the board that contains the yellow part and the on off switch. Your help would be great if you have the values.
@@grahamfranklingf, I'm sorry, but at this moment I cannot help you: I haven't repaired the AV32 model and I don't have the information that you need for the resistor values.
Es normal que caliente el Bafle izquierdo? Cuanto es normal? Gracias
Yes, to some degree it's normal the background plate of the left speaker to be warm during operation.
Thanks you! ;-)
How much to fix mine? Same deal I thik,
Hi,
I assume you are talking about a scenario where you would send me your speakers for repair, however, due to various reasons, I don't think that that would be logistically possible anytime soon.
About the resolve v8
Why does left output speaker sound less louder then the right input
If you are talking about the music in the last test, I checked the source audio files and yes, there is a constant 2-3 dB difference between the levels of the left and the right audio signal (and as you noticed the right one is the louder one).
As I mentioned in the video, during the last test the audio was recorded using a digital recorder and one possible explanation is that it was not directed symmetrically to the speakers (although I wouldn't let that happen at least for that test and I don't expect that much difference even if that had happened).
I haven't noticed any difference between the left and the right speaker output levels during the everyday use before and after the repair but I'll do a more thorough test to clarify this. Thank you for your remark!
Lol good stuff
Hola tengo un problema con los monitores míos son Maudio av40
lo que me sucede es que cuando los enciendo suenan en un volumen muy bajo
los desarme y pude notar que las piezas verdes estaban en muy mal estado avían estallado botando un liquido blanco
aun sirven los monitores pero suenan muy bajos
que me recomiendas
Saludos desde colombia
Hello I have a problem with my monitors are Maudio av40
what happens to me is that when I turn them on they sound at a very low volume
I disassembled them and I could see that the green pieces were in very bad condition, they exploded spilling a white liquid
Monitors still work but sound too low
Hi,
I'm not sure what exactly you are referring to when you say green pieces, but from the rest of your comment it looks like that there are some damaged capacitors. If that's the case, you need to identify and replace them properly. Also, it's important to find the cause why that happened, to avoid repeating the problem again.
If you are not experienced in electronics, I advise you to ask support from a qualified person for this repair.
Best, Goran
Buzz/hum which wasn't there before. Earth or to be more correct the active speakers are now the earth so removal of other earth's on the system will need to be done first...? I don't know
This just happened to me
That DC-offset doesn't look right, mine was 20mV. I have heard that DC-offsets of 100mV and over can damage speakers.
While I also don't like the fact that there is a DC offset of 0.2V on one of the outputs, the dissipated power resulting from this voltage is only 10mW (this is for a 4 Ohms speaker). That will certainly not damage the speaker.
To add insult to injury, mine even came with a bad 3,5mm cable!
What's the value of transformer
I bought it for about 8 euros.
I use the av 4.2 monitors ,i encounter a very unusual problem....
The problem is that when ever i switch on the monitor its plays for a second and then there is no output m..
Sometimes the speakers play for a minute and so and then again no output ....
Can u plz help ..!
Hi,
How experienced are you in repairs in electronics? It's difficult and time consuming to diagnose the issue and provide help this way. However, another viewer put a comment recently describing an issue related with a component in the mute circuit and, at at first glance, it seems that both issues have something in common. Is the power LED on while the playback is muted?
@@GoranDzambazov yes the led is on
@@GoranDzambazov thanks for your reply
@@anirudhanand07_23 I can only advise you to find the datasheet of TDA7265 IC and investigate the mute circuit around the pin 5.
@@GoranDzambazov ok thanks for the help😃
I cant find that transformer anywhere...:(
The transformer used in these speakers is a standard component and it shouldn't be a problem finding it. But, did you definitely confirm that it's defective and that it needs replacement? Typically, the fuse should prevent that to happen.
@@GoranDzambazov Yes, the fuse is all right, and the transformer is shorting out, cause it looks like it melted the insulation. Found one transformer, but its 100v...
@@Manismor Well, then good luck with the repair!
My transformer burn out in mimes so it was replace with a laptop power supply inside of it over a year now still up and running in my studio
My speakers are not getting power but i checked the fuse and its fine
Hi,
Are we talking about AV 40 speakers? Is the mains power present at that outlet? If the mains and the fuse are OK, then the issue needs to be investigated furher and it is likely that the failure is in the power supply section. With the limited information that I have for your problem, that's the only advice I can give you at this moment.
@@GoranDzambazov yes av 40' i checked my power with a multimeter en its present till the transformer i guess i need to check inside the pc board
@@deshwakitofficial8402 Did you check the resistance of the transformer's primary coil?
@@GoranDzambazov thts what i was suspecting.this whole time but i will check it out and get back to you.thnx for your time
I have a pair of these speakers that quite literally woke up our entire house a few minutes ago. They were turned on, connected to my MBP, but nothing was playing and all of a sudden started making a blaring loud and constant hum from the left speaker. The only way to make it stop is to turn the unit off or unplug from the mains. It's so loud that just from getting close enough to stop it, my ears are still ringing about 20 mins later.
Sorry to hear that. It sounds similar to what happened to mine.
These speakers are the worst crap I have ever bought. :(
Sorry to hear that!
Ditto that. I had nothing but buzzing noise from them!