In all the years I worked in a Pan/Technics dealer, I never saw one of these with the lid off - they seemed utterly bombproof; hell, I even owned one myself for a while. Very interesting to see, thank you again sir!
Thanks, this helped me solve the same problem on my microwave for $0.50 in parts. All the repair sites say I needed to buy a $200 controller. Fortunately I found the schematics on line inside a repair manual. Nice to know dim VFD are commonly power supply failures and not related to tube or drivers.
I'm a newbie attempting my first real electronics repair. I picked up an 80s-ish ADC graphic EQ today with a dim VFD for cheap. I just opened it up and found the four big caps on the power supply sitting in dark brown goop, which also partly covered some surrounding links and resistors and such. It looks like there's glue there, but also a much darker substance. I tested them with my LCR-T4 and they check out okay, but because of your experience in this video, I'm assuming they're actually bad. Tomorrow I'm going to source some replacements and hopefully that will solve my problem. Thanks!
Same here. I have a Clock / VU meter I built a few years ago. It shows the levels going into my tube amp I built. Looks cool, just sits on the top of the amp nicely centered between the tubes showing the input from my blutooth receiver into the amp.I have a few clocks I have restored / built with VFD, and I have an old desk calculator that has 12 single digit tubes in it to restore, or repurpose into a clock display.
12voltvids I have maybe 20 or 30 different VU meter and spectrum analyzer tubes. I actually have a tray of NOS 12-point stereo VU meter tubes from Futaba that I ended up turning into an "array" for use as a DIY spectrum analyzer. Should look cool. I even have a stockpile of Sony MXP-3000 mixer VU meter tubes to re-purpose as an audio analyzer. Talk about a fetish haha.
THEtechknight - WOW! were we twins separated at birth? I have the same addiction to Vacuum Fluorescent Displays - especially the BLUE! wikivisually.com/wiki/Vacuum_fluorescent_display I have recently been replacing capacitors in my older XP computers motherboards to bring them back to life. I like to use the Weller WESD51 50W Adjustable Digital Display Soldering Station. My favorite Vacuum Fluorescent Display is in the Roland MKS-70 synthesizer.
I'm hoping to fix a couple of VFD digits on my GE Spacesaver microwave from the '80s. I have two digits that are working fine, so have a good reference. Thanks so much for leaving this out there!
Thanks to this video I was able to repair of a display on a tuner unit, so yes thanks for the information. Changed a couple of capacitors and voila it works
Holy smokes I have one of those. Very similar model : Tuner: ST-G5 Amp: SU-V6X (100 watt) It had a bad cap & dirty vol. control. My intent was to sell it,but now i'm not sure; It sounds great! Thanks to your vid, you confermed operation of the tuner for me. Damn Amp is heavy!
Thanks a lot bro, just solve 1 unit with the same trouble mine us pioneer compact mini component with dim display this video gives me idea what stage and parts to look for and got lucky to find it in single attempt 100v 10uf is what I found
Great work bringing that back to life. I wish more people would do that. I personally would love to and have tried with some things, but my visual impairment limits what I can do with small electronic components.
@20:50, Hybrid Digital radio here in the states....I'm gonna check out that voltage doubler circuit you described in another device that has with no 35v to its vfd. Thanks for the description of that circuit!
is that true? please post a video, there are lcr meters for 150 Usd and Hameg machines where I even do not know if you need a central unit that it works. I think I do not touch Hameg and leave it to the pro’s.
Your videos are always so good, and you explain in real life terms and not jargon. Only problem is I can’t understand your Canadian accent 😀 I’m joking, I have friends in St Catherines and always tease them. Could you please do a video explaining dB, I never fully understand it. Keep up the great videos. Ps I also used to used to work for Sony in the Uk
If you ever come across a Fostex D80 right up to the last in the series i have a d1624 mk2 it has a separate board for every part of the circuit even the regulator and output to external screen has a little circuit with smd ferrite beads. If there was ever a museum for over engineered electronics devices they should be first in the display. I found one blown smd ferrite bead on a double sided board smaller than the palm of my hand after checking everything thats 5 boards 5 schematics. Not a fun unit to work on and thats only counting the boards that effect the display
Great job! I'm having a problem like that with an Optimus tape deck that I pulled out of the closet. Thanks for the tip. I hope that's what's wrong with mine. It's amazing how those caps can go bad with equipment in storage.
Woow.i have a 80s car radio with a tiny floresent tube display with no display.im going to look for the caps near to display.as it's 12v not sure what voltage to display could be
Would bad capacitor possibly be the issue for a display that was showing screwed up digits ? I have an Emmerson three disc cd player... Model. number MS3100. The display is messed up and when I push button to open CD cover, I can hear some noise but the automatic lift wont work either.
Hmm shorting memory capacitors at the end, i think they work ok :-D. Im not supprised that the series capacitor was a bit dead, series reactance and the output being shorted to ground on the positive going phase. It lasted well though. Ive had the filiment supply go low/dead in some units, one had a dead winding on the power transformer, a small secondary transformer was added to fix that. Too expensive to replace a multi-tap special transformer :-(
I was going to ask about this problem before I came across it being that I noticed on items that I've had own like VCRs with these type of displays get weak by time whether its was panasonic or toshiba and etc...... In a case like this if would I be correct to say if the voltages were proper then the chances would likely lie on the display tube itself if the gas has leaked?
Ever come across a Pioneer receiver from the 70's? I had an SX-650 which was (I think) an honest 25 watts per channel. Always loved the old Pioneer Supertuners.
That's right. That's why it is out in the shed. Probably got no covers on it. It was abandoned at the same time as a Sansui 9090. I fixed the 9090, and the owner bitched and complained about a 150 repair bill. Needed 8 new outputs. Wanted to pay me 20 a month. I told him when the bill is paid in full he could have it back. The guy that brought it in way back in 93 or so, while I was still working in the shop brought it directly to me because he had a falling out with the shop owner. I got stung by him before on a repair at the shop, hence he was banned from coming in, so he brought it to me directly. I quoted him the parts plus 60 to repair and he gave me the green light, and then started playing games. In the end he never paid me, and I kept the receiver, and never got on the pioneer, it ended up getting tossed in the shed. The 9090 works perfectly and I have hung onto that piece, which is worth about 1200 last time I checked at the vintage audio shop.
Yes brand and model specific.Every company has had star performers and dogs.The test of time shows which pieces, which were generally high end pieces from the onset hold their value. It's like an old car. There are lots of old cars around, and most are worthless, but ever so often there is one that is worth more. I have such a car myself in storage. It is a 1995 Ford Thunderbird, supercoupe, with metallic chameleon blue paint.The Thunderbird was not a rare car, however 95 was the last year they made the super charged supercoupe.Only 615 rolled off the line with a 5 speed and only 3,400 rolled off the line with the 4 speed automatic. Of those 3400, not all of them had the automatic ride control shocks and traction control.If that wasn't enough, even fewer left the factory with Chameleon Blue paint. The paint color alone was a 4,000 option. Mine has leather throughout, and I kept the original sound system with cassette deck.The car is off the road, hasn't been driven since 2011 (but started regularly) and will be a collector car. In 3 years it will have reached collector status. My son wanted it, but he doesn't drive, and says now he has no interest in cars.
Hello Sir, I have the same problem with a Panasonic SU-CH 40 display. I know something about electronics but not as a pro like you. Even I can measure voltages, got the electrical service scheme, I am a little old for this stuff, but I am sure is some kind of the same issue. Can you help me? thanks for any answer
Picked up the 505 model from a thrift store. This fixed the display!! You rock. It still sounds pretty distorted though, do you recommend to replace all the Caps?
Hi. Thx for the great video. I have a question. I have a Sony Lbt-V902. There is 2 problems with the tuner and equalizer displays. Tuner: Some characters of the tuner display are dimer then the other ones. Equalizer: Right channel display is dimer then the left one on the spectrum analizer display. Are these fixable without changing the displays which are impossible to find replacements? THX
Good work there. We have a 27 year old Kenmore kitchen range that has a dim display on the oven controller board. I read on an appliance web site that it was most likely a electrolytic capacitor that was going bad because it was in that hot environment. This sound like the culprit to you? I am about ready to tear it apart and see if I can fix it.
They were hard to find when they made them because they were very expensive comparatively speaking. I almost bought one, but I opted for the Sony AM Stereo tuner, one I still have, except that there is no more AM stereo, but my sony has wide and narrow IF bands for both AM and FM.Will service it some day. It needs a backup battery and a light in the display, as it uses an LCD with an incandescent bulb for light. I think some nice LEDs are in order.
Now you know the problem. Low voltage to the display. (or the tube is getting weak)My Panasonic DVD recorder is starting to get dim, but I can still see it so no need to service it yet.
I've seen some newer testers that also include diodes, transistors, and inductors. They give you a lot of info including capacitance and inductance. Have you ever tried one of those?
I wonder if there is a HT+ would it be 50v would it be the regulator on the PSU board, I wonder why Technics used a single board when in my unit it is a 5 board solution, I don't know why a X3 capacitor was not used.
EXCELLENT job on all your videos!! You are a great teacher!! Is it possible your ESR meter has a problem? Odd that it would not detect a dead short. What happens if you short the leads together?
Walt Anderson how esr meters work is by injecting a 100 kHz signal and measuring the resistance. when you start an esr meter you short the leads and zero out the meter. capacitor normally block DC current but will pass ac. so this ac signal should pass right through. when a cap normally starts to go bad they pass less ac and thus the esr or equivalent series resistance goes up. in this case the capacitor dead shorted, which allowed the signal from the esr meter to pass through like a good cap would except this was shorted. the regular ohms meter caught this as it would normally appear open to DC resistance testing.
Hi there again. I have a Sony MDS-JB920 Minidisc player with a slightly dim display esp on the 2 level meter lights could you please possibly point me in the right direction to the faulty part. Many Thanks
Actually I can't remember the last time I found a dead shorted electrolytic it was that long ago. Usually they go open, and when you bridge another on in parallel it fixes it. Needless to say when they short it makes finding them a little more of a challenge as the weapon of choice, the ESR tester is totally useless in this case. This one had me stumped for awhile, until I got the schematic. Then it was a relatively simple task to test. Once I disconnected the resistor to isolate the supply it was the first part I checked.
I’m a beginner at repairing electronics! So if a bad capacitor is making a screen dim. Is the bad capacitor likely to be or will it always be on the power supply? Thanks for your time. I just found your channel and enjoy your videos.
Not always no. Some times the display tube goes bad. If the voltages to the tube were correct and it is still dim then the tube is bad. In thus case there was a voltage problem and that cap was part of a voltage doubler circuit that shorted.
Hi, awesome video. I have a VFD display in a 12v BrakeSmart brake controller in my pickup that comes on full brightness for 1.5 seconds, then dims to 0. Likely a bad cap. Can I pay you to fix this? How do I get in touch with you? Darin
i actualy have the same problem with my philips dolby... sometimes its bright and sometimes i just can read in what mode it is. is this the same problem? Can you please help me repair this screen, i can solder and i have a service manual to find out what is broke but im not smart enough :)
Hello i got philips micro system mcm2320 and when i plug into power i cant turn device on only red light is showing near on/of button so i press on button but nothing happen is that capacitor or electrical condenser if u know tell me coz i dont want drop it in garbage is nice device i hope u know coz u fix a lot of that device thank you.
That one scared the shite out of me. The client had complained that it wasn't holding memory as well, and I noticed that the connection was a little rough looking, and there was crud around the top side so I figured I would put the cap to see if it was leaking. (it wasn't). Either it, or it's series connected neighbour was charged. Only 2.5 volts but it went off with a bang. Hey the memory works now! I was going to leave that out but I figured I would put it in for a surprize at the end.
Went to resolder the + side of the backup capacitor as the client said it was losing memory. The connection had gone bad, and opened up with that bit 3.3Farad capacitor still charged. Only 2 or so volts but it went off with a bang.
12voltvids I can imagine this was quite a surprise ;D, 3.3 Farad are quite something to wake you up ;). Very cool repairs you do and I had a good laugh :). Thank you :).
First you have to determine why it is dim.Check the drive voltages. If low you have to find the power supply component that is causing it. If the voltages are correct then you have a bad display.
Filaments are usually pretty low as far as voltage across the filaments go. That is just to warm them up. There is typically a high negative voltage applied to the filaments -30v or so with respect to ground, or a high positive +40-+60 on the anodes. If it uses a high anode voltage the DC offset on the filaments will be close to ground and the filaments may be powered by AC. Usually it is in the 3V range. Enough to heat them up but not produce much if any visible light.
Mark Zacharias no backlight on the 12 and I wouldn't want one. suck the batteries down fast. my shop is bright enough but I guess if you are testing a furnace or working in a dark closet it could be handy.
So is this fault never down to a weak vacuum flourescent display? A lot of the 2001-2005 Sony receivers suffered from getting these extrememly dim displays 10 years later...
A VFD can go bad, but they usually do last a long time. If the filament is driven too hard it can boil off the electron emission coating, but if properly designed they can go for a long, long time. My microwave oven has been in 24 hour service since 1989, and I have a clock that goes back to 1979 and they are still bright as anything.Usually it is the power supply losing voltage, especially in these units that use a voltage doubler or Tripler as in this one. Units that have a separate 30v winding on the transformer are much more reliable.
12voltvids I'll note that thank you for that. I just always previously thought it was the VFD because more used areas were dimmer than the ones that were not used as much on these Sony receivers such as the coax or DTS light. So I take it each segment has it's individual capacitor, and over the years failure occurs resulting in some parts of the display being dimmer than the others? I do repair these as a side projector extra money, and sell them online on eBay. Sometimes though I just throw them out because of the really weak VFD, as I was unaware until now they were not likely to be the fault. Feel stupid now lol!
The display segments can wear out. The phosphor will eventually get weaker for sure. If the entire display is dim, then you have to check for correct supply voltages. If the voltages are correct and the display is still dim, then the display is the fault.I did have a clock display that was bad. I replaced it with another one, and I had to make up extension wires to go to the board to wire it correctly. I have a video documenting the old dim display, and the new one.
ESR is just a measurement to show how well a capacitor passes an AC signal. It stands for equivalent Series resistance, and is based on the fact that electrolytic capacitors have a very low impedance to AC. That is why they are used in coupling stages together.Normally you can measure ESR in circuit, because the voltage used by the ESR meter is very low, less than .5 volts therefore it will not cause semiconductors to go into conduction.This capacitor had dead shorted, and therefore was giving the ESR meter a false low reading so it looked good in circuit in and out of circuit on the ESR meter. Had it not dead shorted, it would have measured probably almost open on the ESR meter and would have been spotted in a second, because that was the first capacitor I measured with the ESR meter. It wasn't until I had ruled all the others out that I started to disconnect parts, and use the old old multimeter that I found this. So this is a good learning video to show that as valuable ESR meters are in service, they can give false readings, and send the service tech down the wrong path.
In all the years I worked in a Pan/Technics dealer, I never saw one of these with the lid off - they seemed utterly bombproof; hell, I even owned one myself for a while. Very interesting to see, thank you again sir!
This is the first one I have seen too. As you said, bombproof.
Thanks, this helped me solve the same problem on my microwave for $0.50 in parts. All the repair sites say I needed to buy a $200 controller. Fortunately I found the schematics on line inside a repair manual. Nice to know dim VFD are commonly power supply failures and not related to tube or drivers.
always impressive how they get mixed signal circuits working properly on a single sided FR2 PCB
I'm a newbie attempting my first real electronics repair. I picked up an 80s-ish ADC graphic EQ today with a dim VFD for cheap. I just opened it up and found the four big caps on the power supply sitting in dark brown goop, which also partly covered some surrounding links and resistors and such. It looks like there's glue there, but also a much darker substance. I tested them with my LCR-T4 and they check out okay, but because of your experience in this video, I'm assuming they're actually bad. Tomorrow I'm going to source some replacements and hopefully that will solve my problem. Thanks!
I absolutely love VFD displays, Unfortunately, I have an addiction to them so I ended up having a vast collection of random VFD displays.
Same here. I have a Clock / VU meter I built a few years ago. It shows the levels going into my tube amp I built. Looks cool, just sits on the top of the amp nicely centered between the tubes showing the input from my blutooth receiver into the amp.I have a few clocks I have restored / built with VFD, and I have an old desk calculator that has 12 single digit tubes in it to restore, or repurpose into a clock display.
12voltvids I have maybe 20 or 30 different VU meter and spectrum analyzer tubes. I actually have a tray of NOS 12-point stereo VU meter tubes from Futaba that I ended up turning into an "array" for use as a DIY spectrum analyzer. Should look cool. I even have a stockpile of Sony MXP-3000 mixer VU meter tubes to re-purpose as an audio analyzer. Talk about a fetish haha.
THEtechknight - WOW! were we twins separated at birth? I have the same addiction to Vacuum Fluorescent Displays - especially the BLUE!
wikivisually.com/wiki/Vacuum_fluorescent_display
I have recently been replacing capacitors in my older XP computers motherboards to bring them back to life. I like to use the Weller WESD51 50W Adjustable Digital Display Soldering Station. My favorite Vacuum Fluorescent Display is in the Roland MKS-70 synthesizer.
I'm hoping to fix a couple of VFD digits on my GE Spacesaver microwave from the '80s. I have two digits that are working fine, so have a good reference. Thanks so much for leaving this out there!
Thanks to this video I was able to repair of a display on a tuner unit, so yes thanks for the information. Changed a couple of capacitors and voila it works
Holy smokes I have one of those. Very similar model :
Tuner: ST-G5
Amp: SU-V6X (100 watt)
It had a bad cap & dirty vol. control. My intent was to sell it,but now i'm not sure; It sounds great! Thanks to your vid, you confermed operation of the tuner for me. Damn Amp is heavy!
Thanks a lot bro, just solve 1 unit with the same trouble mine us pioneer compact mini component with dim display this video gives me idea what stage and parts to look for and got lucky to find it in single attempt 100v 10uf is what I found
Great work bringing that back to life. I wish more people would do that. I personally would love to and have tried with some things, but my visual impairment limits what I can do with small electronic components.
@20:50, Hybrid Digital radio here in the states....I'm gonna check out that voltage doubler circuit you described in another device that has with no 35v to its vfd. Thanks for the description of that circuit!
thanks for taking you time and knowledge to help us inecsperianced.
Get yourself an lcr meter. It will test capacitance and esr at the same time in circuit. Saves alot of time
is that true? please post a video, there are lcr meters for 150 Usd and Hameg machines where I even do not know if you need a central unit that it works. I think I do not touch Hameg and leave it to the pro’s.
i am your big fan and watched almost video
i am also a electronic engineer and electronic r&d is my passion
Your videos are always so good, and you explain in real life terms and not jargon.
Only problem is I can’t understand your Canadian accent 😀
I’m joking, I have friends in St Catherines and always tease them.
Could you please do a video explaining dB, I never fully understand it.
Keep up the great videos.
Ps I also used to used to work for Sony in the Uk
technics always make us take the hole thing apart. it is good stuff at the end
:)
you are awesome,there is no el.item you would not be able to repair,very educational too,thanks for your educat.videos
thanks Dave for teaching me hifi electronic repairs.
Sry sir but i have to point out that you showed us the 718 with your little finger not the 716. 716 ist down/left from 718. Nice video. Keep it up
I really learned something here :I will not rely on my ESR meter alone
Some have built in antennas. My old receiver had a Ferrite rod for AM. But it had 300ohm connector screws for FM.
If you ever come across a Fostex D80 right up to the last in the series i have a d1624 mk2 it has a separate board for every part of the circuit even the regulator and output to external screen has a little circuit with smd ferrite beads. If there was ever a museum for over engineered electronics devices they should be first in the display. I found one blown smd ferrite bead on a double sided board smaller than the palm of my hand after checking everything thats 5 boards 5 schematics.
Not a fun unit to work on and thats only counting the boards that effect the display
Great video as usual. The only thing that would make it better would be a broom and trash can
Great job! I'm having a problem like that with an Optimus tape deck that I pulled out of the closet. Thanks for the tip. I hope that's what's wrong with mine. It's amazing how those caps can go bad with equipment in storage.
Well explained....Thank you very much...I have Technics SC-CH700 and amplifier VFD has the same issue and I need to repair it .please guide me.
Woow.i have a 80s car radio with a tiny floresent tube display with no display.im going to look for the caps near to display.as it's 12v not sure what voltage to display could be
Very interesting and useful
I like this intro music the best.
Good Job 👍🏻
Would bad capacitor possibly be the issue for a display that was showing screwed up digits ? I have an Emmerson three disc cd player... Model. number MS3100. The display is messed up and when I push button to open CD cover, I can hear some noise but the automatic lift wont work either.
I have a E66 Technic , but I have a problem , all the buttons are blinking .
Hmm shorting memory capacitors at the end, i think they work ok :-D.
Im not supprised that the series capacitor was a bit dead, series reactance and the output being shorted to ground on the positive going phase.
It lasted well though.
Ive had the filiment supply go low/dead in some units, one had a dead winding on the power transformer, a small secondary transformer was added to fix that.
Too expensive to replace a multi-tap special transformer :-(
I was going to ask about this problem before I came across it being that I noticed on items that I've had own like VCRs with these type of displays get weak by time whether its was panasonic or toshiba and etc...... In a case like this if would I be correct to say if the voltages were proper then the chances would likely lie on the display tube itself if the gas has leaked?
Ever come across a Pioneer receiver from the 70's? I had an SX-650 which was (I think) an honest 25 watts per channel. Always loved the old Pioneer Supertuners.
I have an old pioneer receiver that has been sitting in a shed for 23 years, so it is probably shot beyond repair by now.
Yeah, those things were built in layers so they're very labor intensive to rebuild. A lot of wire wound connections.
That's right. That's why it is out in the shed. Probably got no covers on it. It was abandoned at the same time as a Sansui 9090. I fixed the 9090, and the owner bitched and complained about a 150 repair bill. Needed 8 new outputs. Wanted to pay me 20 a month. I told him when the bill is paid in full he could have it back. The guy that brought it in way back in 93 or so, while I was still working in the shop brought it directly to me because he had a falling out with the shop owner. I got stung by him before on a repair at the shop, hence he was banned from coming in, so he brought it to me directly. I quoted him the parts plus 60 to repair and he gave me the green light, and then started playing games. In the end he never paid me, and I kept the receiver, and never got on the pioneer, it ended up getting tossed in the shed. The 9090 works perfectly and I have hung onto that piece, which is worth about 1200 last time I checked at the vintage audio shop.
12voltvids Woah!!! Had no idea that an old receiver could be worth that much. I do understand that the value is brand and model specific.
Yes brand and model specific.Every company has had star performers and dogs.The test of time shows which pieces, which were generally high end pieces from the onset hold their value. It's like an old car. There are lots of old cars around, and most are worthless, but ever so often there is one that is worth more. I have such a car myself in storage. It is a 1995 Ford Thunderbird, supercoupe, with metallic chameleon blue paint.The Thunderbird was not a rare car, however 95 was the last year they made the super charged supercoupe.Only 615 rolled off the line with a 5 speed and only 3,400 rolled off the line with the 4 speed automatic. Of those 3400, not all of them had the automatic ride control shocks and traction control.If that wasn't enough, even fewer left the factory with Chameleon Blue paint. The paint color alone was a 4,000 option. Mine has leather throughout, and I kept the original sound system with cassette deck.The car is off the road, hasn't been driven since 2011 (but started regularly) and will be a collector car. In 3 years it will have reached collector status. My son wanted it, but he doesn't drive, and says now he has no interest in cars.
That was not a leaking cap that was old dry glue they glued them to make sure there was no chance of moving wich may or may not cause a short
The cap was internally shorted
Last sec.... LOL. Good video and nice tuner!
Yes it is a nice tuner. One of the better ones.
Indeed ! ^^
Nice video, with an interesting fail (I mean the way the capacitor failed, of course).
Not referring to blowing the tip off my soldering iron at the end with the charged 3.3F capacitor!
I wouldn't make fun of that. Thanks for all the videos, I've been
watching them for quite a long time now, learning a lot of things. Many
thanks !
Wish he'd tell me how to fix my denon amp it won't come off standby
Hello Sir, I have the same problem with a Panasonic SU-CH 40 display. I know something about electronics but not as a pro like you. Even I can measure voltages, got the electrical service scheme, I am a little old for this stuff, but I am sure is some kind of the same issue. Can you help me? thanks for any answer
Wonderful repair!!!
Picked up the 505 model from a thrift store. This fixed the display!! You rock. It still sounds pretty distorted though, do you recommend to replace all the Caps?
Hi. Thx for the great video. I have a question. I have a Sony Lbt-V902. There is 2 problems with the tuner and equalizer displays. Tuner: Some characters of the tuner display are dimer then the other ones. Equalizer: Right channel display is dimer then the left one on the spectrum analizer display. Are these fixable without changing the displays which are impossible to find replacements? THX
Good work there. We have a 27 year old Kenmore kitchen range that has a dim display on the oven controller board. I read on an appliance web site that it was most likely a electrolytic capacitor that was going bad because it was in that hot environment. This sound like the culprit to you?
I am about ready to tear it apart and see if I can fix it.
Hello i have a Technics SA-AX720 and the Display have the same problem. have any one repaired it and can say how can i repair it. nice video
I really like that receiver. I wish I could find one somewhere. I'm sure these are hard to find.
They were hard to find when they made them because they were very expensive comparatively speaking. I almost bought one, but I opted for the Sony AM Stereo tuner, one I still have, except that there is no more AM stereo, but my sony has wide and narrow IF bands for both AM and FM.Will service it some day. It needs a backup battery and a light in the display, as it uses an LCD with an incandescent bulb for light. I think some nice LEDs are in order.
Nice! Looking forward to that video.
I have a Technics amplifier from 93 that's starting to show this problem. Year after year it gets little bit dimmer.
Now you know the problem. Low voltage to the display. (or the tube is getting weak)My Panasonic DVD recorder is starting to get dim, but I can still see it so no need to service it yet.
hello everyone knows that the condensers will dry after 15-25 years and need to be replaced. You would not have searched much
I've seen some newer testers that also include diodes, transistors, and inductors. They give you a lot of info including capacitance and inductance. Have you ever tried one of those?
Lots of new testers that do much. I don't have any of the new ones. I don't do enough electronics work to justify one.
I have a Nakaamchi ST-7 tuner with some incomplete LED station numbers. Is this repairable?
I wonder if there is a HT+ would it be 50v would it be the regulator on the PSU board, I wonder why Technics used a single board when in my unit it is a 5 board solution, I don't know why a X3 capacitor was not used.
EXCELLENT job on all your videos!! You are a great teacher!! Is it possible your ESR meter has a problem? Odd that it would not detect a dead short. What happens if you short the leads together?
Walt Anderson
how esr meters work is by injecting a 100 kHz signal and measuring the resistance. when you start an esr meter you short the leads and zero out the meter.
capacitor normally block DC current but will pass ac. so this ac signal should pass right through. when a cap normally starts to go bad they pass less ac and thus the esr or equivalent series resistance goes up. in this case the capacitor dead shorted, which allowed the signal from the esr meter to pass through like a good cap would except this was shorted. the regular ohms meter caught this as it would normally appear open to DC resistance testing.
Thanks! Makes sense. Again your videos are the best! 😁
Good job thank you
love you videos!
ive had noting but trouble with rubycon caps they are garbage
Hi there again.
I have a Sony MDS-JB920 Minidisc player with a slightly dim display esp on the 2 level meter lights could you please possibly point me in the right direction to the faulty part.
Many Thanks
Have no clue.
I can send you a link to the service manual if it would help.
www.manualslib.com/download/720756/Sony-Mds-Jb920.html
@@johnny1408 and how would that help ? I would need to make measurements to even make an educated guess.
very good , thanks ...
I used to have that receiver and I have no idea whatever happened to it 😕
Nice repair
A very well done video. I learned a lot. Is it more common to find an open or a shorted capacitor?
Thanks a lot, Tom
Actually I can't remember the last time I found a dead shorted electrolytic it was that long ago. Usually they go open, and when you bridge another on in parallel it fixes it. Needless to say when they short it makes finding them a little more of a challenge as the weapon of choice, the ESR tester is totally useless in this case. This one had me stumped for awhile, until I got the schematic. Then it was a relatively simple task to test. Once I disconnected the resistor to isolate the supply it was the first part I checked.
Thanks so much for the quick answer. Darn it, I learned ANOTHER useful thing or two! :-)
Tom
I’m a beginner at repairing electronics! So if a bad capacitor is making a screen dim. Is the bad capacitor likely to be or will it always be on the power supply? Thanks for your time. I just found your channel and enjoy your videos.
Not always no. Some times the display tube goes bad. If the voltages to the tube were correct and it is still dim then the tube is bad. In thus case there was a voltage problem and that cap was part of a voltage doubler circuit that shorted.
12voltvids thanks!
Hi, awesome video. I have a VFD display in a 12v BrakeSmart brake controller in my pickup that comes on full brightness for 1.5 seconds, then dims to 0. Likely a bad cap. Can I pay you to fix this? How do I get in touch with you? Darin
i actualy have the same problem with my philips dolby... sometimes its bright and sometimes i just can read in what mode it is. is this the same problem?
Can you please help me repair this screen, i can solder and i have a service manual to find out what is broke but im not smart enough :)
Couldn't tell you. Not familiar with Philips.
Hello i got philips micro system mcm2320 and when i plug into power i cant turn device on only red light is showing near on/of button so i press on button but nothing happen is that capacitor or electrical condenser if u know tell me coz i dont want drop it in garbage is nice device i hope u know coz u fix a lot of that device thank you.
First thing to check is the power button itself. Next, I would look for bad solder connections. Then start looking for bad caps.
I can not help you with my problem with dat player ???
That's an interesting repair :), well done. You did not short your iron at the end, did you haha ;D.
That one scared the shite out of me. The client had complained that it wasn't holding memory as well, and I noticed that the connection was a little rough looking, and there was crud around the top side so I figured I would put the cap to see if it was leaking. (it wasn't). Either it, or it's series connected neighbour was charged. Only 2.5 volts but it went off with a bang. Hey the memory works now! I was going to leave that out but I figured I would put it in for a surprize at the end.
Went to resolder the + side of the backup capacitor as the client said it was losing memory. The connection had gone bad, and opened up with that bit 3.3Farad capacitor still charged. Only 2 or so volts but it went off with a bang.
12voltvids
I can imagine this was quite a surprise ;D, 3.3 Farad are quite something to wake you up ;).
Very cool repairs you do and I had a good laugh :). Thank you :).
Vacuun fluorescent display ... I wonder if I've ever seen one.
Hi.i have a technics slp1200 cd player.the display is dim in places.will the display be on its way out.or a supply issue.any advice would be great.
michael allen
You need to check voltages. If voltages are correct then the display could be the issue of the driver ic.
Would this be true, if only part of the display was dim also? Or would I be looking elsewhere
Yes partial dim displays are usually capacitors starting to fail.
how do you go about brightening a vfd display?
First you have to determine why it is dim.Check the drive voltages. If low you have to find the power supply component that is causing it. If the voltages are correct then you have a bad display.
its the display in the sony MHC-551 hifi it works but its dim. i found 2 bad cps causing speaker hum though,
Ill have a look on the PCB it has voltage makings, ill take some measurements thanks m8
Hello again m8, ive just checked and the voltage to the VFD's filament is 1.7v is this right you think? seems a little low?
Filaments are usually pretty low as far as voltage across the filaments go. That is just to warm them up. There is typically a high negative voltage applied to the filaments -30v or so with respect to ground, or a high positive +40-+60 on the anodes. If it uses a high anode voltage the DC offset on the filaments will be close to ground and the filaments may be powered by AC. Usually it is in the 3V range. Enough to heat them up but not produce much if any visible light.
Does that Fluke 12 have a backlight? Modded? I own several Flukes including a 12 and mine doesn't have a backlight.
Mark Zacharias
no backlight on the 12 and I wouldn't want one. suck the batteries down fast. my shop is bright enough but I guess if you are testing a furnace or working in a dark closet it could be handy.
Guess it was just some artifact in the video.
So is this fault never down to a weak vacuum flourescent display?
A lot of the 2001-2005 Sony receivers suffered from getting these extrememly dim displays 10 years later...
A VFD can go bad, but they usually do last a long time. If the filament is driven too hard it can boil off the electron emission coating, but if properly designed they can go for a long, long time. My microwave oven has been in 24 hour service since 1989, and I have a clock that goes back to 1979 and they are still bright as anything.Usually it is the power supply losing voltage, especially in these units that use a voltage doubler or Tripler as in this one. Units that have a separate 30v winding on the transformer are much more reliable.
12voltvids I'll note that thank you for that. I just always previously thought it was the VFD because more used areas were dimmer than the ones that were not used as much on these Sony receivers such as the coax or DTS light. So I take it each segment has it's individual capacitor, and over the years failure occurs resulting in some parts of the display being dimmer than the others? I do repair these as a side projector extra money, and sell them online on eBay. Sometimes though I just throw them out because of the really weak VFD, as I was unaware until now they were not likely to be the fault. Feel stupid now lol!
The display segments can wear out. The phosphor will eventually get weaker for sure. If the entire display is dim, then you have to check for correct supply voltages. If the voltages are correct and the display is still dim, then the display is the fault.I did have a clock display that was bad. I replaced it with another one, and I had to make up extension wires to go to the board to wire it correctly. I have a video documenting the old dim display, and the new one.
elna cap?
Nichicon if i remember
good
good job!where do you find your schematics at.
I pressed the easy button. G O O G L E!
Heh ESR was good, but capacitance was what it was and because of that cap was shorted it's ESR was good. I'm I right?
ESR is just a measurement to show how well a capacitor passes an AC signal. It stands for equivalent Series resistance, and is based on the fact that electrolytic capacitors have a very low impedance to AC. That is why they are used in coupling stages together.Normally you can measure ESR in circuit, because the voltage used by the ESR meter is very low, less than .5 volts therefore it will not cause semiconductors to go into conduction.This capacitor had dead shorted, and therefore was giving the ESR meter a false low reading so it looked good in circuit in and out of circuit on the ESR meter. Had it not dead shorted, it would have measured probably almost open on the ESR meter and would have been spotted in a second, because that was the first capacitor I measured with the ESR meter. It wasn't until I had ruled all the others out that I started to disconnect parts, and use the old old multimeter that I found this. So this is a good learning video to show that as valuable ESR meters are in service, they can give false readings, and send the service tech down the wrong path.
Yes I agree with you. That was really nice video about how difficult phenomenons can show up in real world. Thanks again for good information.
Oh snap!
You definitely cannot rely on anyone piece of gear to completely tested capacitor.
The best piece of test equipment is located between your ears!
25 sec intro... really?
technics,CRAP. wouldnt but buy this modern junk crap