I like the troubleshooting explanation, and the follow ups after getting replacement parts. Well done.
@larrydavis4064
2 жыл бұрын
Thanks for sharing. Have a JVC RX884 not audio on one channel. Suspect it may have the same issue.
@mguess
2 жыл бұрын
There's a good chance.
@dwoodog
4 жыл бұрын
Nice fix, you made it easy to follow what you were doing, and best of all the JVC lives to die another day.
@mguess
4 жыл бұрын
Thanks for watching and commenting, and yes the JVC receiver is still working fine nearly 4 years later.
@emprsnm9903
4 жыл бұрын
Those protection relays, I swear. Have two JVC RX's (platinum color era early-mid 90s) where the center & rear channels went out. Cleaned the relay contacts (desoldering and disassembling the things). Afterward, by turning the surround on & off, they would engage and hold, but hit and miss whether sound would come out. Bah! I should have just replaced them outright, so much time and care trying to restore "pitted" contacts :) Nice to know it's not just me having wear problems with the relays! Also, shouldn't the VFD be amber? I think they put an amber filter (colored translucent plastic) in that era. A previous repairman must of lost it, because they can come out/fall out when the front panel is removed. Kinda cool how it turned white-green into amber, and solid-green into red.
@mguess
4 жыл бұрын
Thanks for the comments. That was a fun little project, I learned quite a bit. You may be right on the display color, it does seem a little bright. If there was a filter on the display it was missing by the time I got the unit.
@robertopereira403
7 жыл бұрын
Dear Sir. Please, do you have the front door hinges on the JVC RX-1050? Or do you know who you are? Thanks. Roberto from Brazil.
@williamstaten8102
7 жыл бұрын
Cool video hope to see more. I just pop the top off those relays and sand the contacts.
@mguess
7 жыл бұрын
I did actually take the top off the relay after ordering a new one. I considered cleaning up the contacts but decided to just install the new relay, fairly cheap fix.
@1959Berre
7 жыл бұрын
When I restore an amplifier, I always polish the contact points of the output relay with just a little metal polish compound on a piece of thin carton.
@christromblee5589
7 жыл бұрын
80566 anyway you can contact me? i have a tiny issue but cant seem to figure ot out and to talk to anyone cost too much money. just to talk to someone! if you get this contact me @ Chrisrobinson355@yahoo.com
@thomaschase1719
4 жыл бұрын
mguess got a link for that relay my rx-403, a longtime loadstone had those same symptoms when my kid brother went hogshit crazy with my newly acquired and only decent stereo along with ‘help’ as being defined by Greeks bearing gifts I’d love to fix it myself.
@curtwells4905
3 жыл бұрын
at 4:52 in, you can see- on the lower part of the image- a bunch of post-factory installed jumpers- what was all that? A previous repair? Thanks!
@mguess
3 жыл бұрын
I just noticed the jumpers in the video. I don't remember them while working on the amp. Not sure if they were a previous repair or factory mod.
@waupfm
8 ай бұрын
I just picked up a RX 401, but it came without a remote or manual. I was wondering if you might create a video that shows how to work the EQ? From what I understand, there are 5 EQ presets and 5 EQ presets that can be programmed by the user. I am finding the presets but I would like to program the EQ user presets. Hope you can help with this. Thanks
@mguess
8 ай бұрын
I've never played with the EQ presets on that unit. I do have the service manual if that will help you.
@DanielFoley75
Жыл бұрын
I have one of these and I love it but the other day the LCD screen went dark. Any suggestions on how to troubleshoot and repair? I am familiar with vintage stereos but not ones with this many integrated circuits
@mguess
Жыл бұрын
Does the display still work but just not illuminated? if so I'd look into the light source. I'm not sure how that works on that LCD display. It may be internal to the LCD unit.
@laidback93
Жыл бұрын
I have an RX-201 and have no sound on the right channel. I suspect it could be the speaker relay, but not quite sure as I have another weird issue. If you press up and down on the balance slider, the left channel will short out. I shot some deoxit in tone/balance controls and the volume pot. No change. Unfortunately, I'm not skilled with electronics repair, nor do I know my way around a soldering iron. I hate to throw this receiver away as it does sound very nice.
@mguess
Жыл бұрын
Have you tried different input channels to see if some of the issues may be input related? You might want to try the old "pat on the top and side" to see if the issue is contact related. Based on the problem description I would suspect some bad solder joints on the main circuit board. I'd be happy to take a look at it for you if you want to send it to me. If so contact me at mguessva@gmail.com.
@laidback93
Жыл бұрын
@@mguess I’m going to mess around with it more and try your suggestions. I just may end up shipping it to you. I have several other receivers, but would hate to throw it away.
@sebamariano
2 жыл бұрын
I have a receiver that turns on and does not emit sound, if I increase the volume with the control it makes pac at each touch. I have no idea about electronics, but I was researching and it has transistors 2SB1429 first in green and 2SD2155 in black, I'm afraid they are burnt and are no longer available.
@brianhenry2134
6 жыл бұрын
I have the same problem with a jvc RX-R85 I can't find a replacement relay (RY-901) for my receiver. Could you give me the part number for that Panasonic Relay. Thanks, Brian Henry
@mguess
6 жыл бұрын
I think I used this relay or something similar. I had to modify the pins on the relay slightly since it wasn't an exact replacement. Check the dimensions. www.ebay.com/itm/NEW-DG2SU-DEC-24VDC-Replacement-Speaker-Protection-Relay-GOLD-CONTACTS-NEW/183256591094?hash=item2aaaf1aaf6:g:RUoAAOSwllpbFCn~ I also found the cable that connects the source selection board to the amp board. I found a poor connection on this cable. Good luck.
@davidecarozza8228
3 жыл бұрын
Thanks for the video, very helpful. Have the same unit and it seems to be overheating. Works well for a while, then cuts out. Any chance you could link to the schematics? Or any idea what your first guess would be for the culprit? Opened it up, nothing immediately obvious.
@mguess
3 жыл бұрын
That unit has some high wattage resistors that it uses to drop voltage for various sections of the circuit. They get very hot. I would start with looking at the connections of those resistors. I have the service manual in PDF format which contains the schematics. I can send it to you if you want to send me you email address.
@TroyPalenski
Жыл бұрын
I have the JVC R-X220 synthesizer receiver that bought 35 years ago new I recently was using it then the screen shut off & power went out, I noticed that the thing that looks likexa transformer was very hot but it won't turn on anymore what do you think could be wrong with it? the fuse is ok but the thing that looks like a transformer smells burnt & very hot as I mentioned, I want to get it fixed you have any idea what it is? I don't want to toss it.
@mguess
Жыл бұрын
It sounds like the problem is in the power supply somewhere but it's hard to say where without troubleshooting.
@TroyPalenski
Жыл бұрын
@@mguess yes I was wondering the same thing, I have to try to find an electronic repair shop here in southern cal hopefully it can be fixed.
@servirepuestosjmserviciote7981
8 жыл бұрын
HELLO FRIEND I AM WRITTEN IN YOUR KZitem CHANNEL A GREETING FROM VENEZUELA I HAVE A RECEIVER JVC RX-803VBK WHEN I CONNECT IT TO THE LINE OF AC LIGHTS THE STAMBY LED, IT SOUNDS AS THE RELEASE ACTION THEN I PRESSURE POWER AND I BURN THE INPUT FUSE , I COULD SAY WHERE TO START WITH THE REPAIR ??
@mguess
8 жыл бұрын
It sounds like a power supply problem. Be careful, there are dangerous high voltages present in the power supply area. Ask someone with electronics experience for help if you are not familiar with electronics troubleshooting.
@calyps0man
7 жыл бұрын
Hi. I have a problem with JVC RX884R. I got all the voltages but nothing on the right channel, both in headphones and speaker outputs. Doesnät matter which input, it's the same thing even on the radio.. Could it be the selectr chip problem as well ?Relays were replaced many times. There's actually 2 pairs of outputs for the front speakers and 2 buttons to switch between them. Strangely, one pair doesn't switch anymore at all and the music is playing in one channel even when the switch is off. I'm quite confused where to look for the problem at this point. All of the big transistors are fine , nothing is burnt.
@mguess
7 жыл бұрын
It sounds like you may need to do some signal tracing. A schematic is a must. An oscilloscope helps here but you can use an ac voltmeter. Input a signal from a laptop or smart phone running a signal generator app, available online for free. Set the signal generator to output a 1kHz sine wave. This should be about 500 mV. Trace the signal from the input until it disappears. Sounds easy but sometimes a pain to do.
@calyps0man
7 жыл бұрын
Thanks for the suggestion, I will try that.
@calyps0man
7 жыл бұрын
I followed your advice and tried to trace the signal from one of the input boards according to the service manual. I was right, it was the selector switch IC completely blown, just like in your case. It supplied 10V in the right channel ,and now that I tested it again, even the left channel went oout too with signal not passing through the chip and showing 0.07 mv. Once I took out that whole input board, the amplifier recovered. Except there is still an issue of the speakers playing regardless of the speaker selector keys . I'll try to diagnose that part some more.
@calyps0man
7 жыл бұрын
Can you please point me in the right direction once more.My speakers and headphones keep switching on all at once and I can't turn them off anymore. Can you explain how do relays activate? There's 5 of them. 2 for 2 pairs of front speakers, 2 for rear and center. 1 for headphones.At the moment once i turn on the receiver all 5 switch on all at once, but they are supposed to switch on only when I select it by pressing the speaker buttons. So I measured the voltages and it seems each relay receives constant 25v (they are rated 24v, 5a) on one side of the coil, while the other side is changed depending if the speaker button is pressed or not. So the second contact of the relay coil gets between 4-6 volts, and raises to 9 when the key is pressed. On the other relay, it actually reduces for some reason from 6 to 4 when i select that one. However the relays don't react to any buttons (subsequently voltage changes), they are always on now... The voltages are regulated by digital transistors that might be faulty? They get the signal from the control chip once the button is pressed and they receive about 2-4 volts before amplifyng the signal to the relays. .
@mguess
7 жыл бұрын
I don't have the schematic for your receiver so I can't really help too much. My receiver is a much older 2 channel stereo only unit. However most relays in the receivers that I have worked on are operated in a similar fashion. Like you observed, one side of the coil is connected to a constant voltage and the other side is "pulled low" by some transistor device (either discrete or IC) to cause current to flow and energize the relay. So when the relay is energized you should see a constant voltage on one side of the coil and a somewhat lower or even 0 volts on the other side of the coil (the side connected to the control device). When the relay is de-energized you should see the same voltage on both sides of the coil, 25 volts in your case. Since all of your relays are exhibiting the same problem I would look for something that they have in common. Look for cracked solder joints and poor grounds on the back side of the circuit board. Good luck and let me know how it's going.
@1959Berre
7 жыл бұрын
Get yourself a solder removing pump to clear the leads of the components prior to removing them. It's a cheap piece of equipment. I could not live without it. By sucking the solder joints, the chip would fall right out of the PCB without destroying it's pins. That way you will not destroy traces on the board neither.
@mguess
7 жыл бұрын
Yep, it's on my list of equipment to acquire.
@LuigiPede
8 ай бұрын
Have ju the elttric diagram for rx 503?
@mguess
7 ай бұрын
Sorry, I don't. You may be able to find one online.
@fcolmedo
7 жыл бұрын
I have a similar receiver with the same problem, both channels has no sound. I suspect it's the TA317P IC, but I don't have the schematics. Could you please send me the pin out because I can't see clearly on the screen (16:58 min). Thank you
@mguess
7 жыл бұрын
I found the datasheet for the protection relay here, pdf1.alldatasheet.com/datasheet-pdf/view/86921/TOSHIBA/TA7317P.html
@emilionelsonlitsuri99
4 жыл бұрын
Não consigo conectar o bluetooth no JVC RX-N390DVD
@adelhelmy2812
7 ай бұрын
Hi there ... I'm not sure if anyone will see my comments after 7 years since this video was uploaded but I'll give it a try. I live in Egypt and have this same amplifier. unfortunately the input transformer is showing an open circuit on the primary side. I want to try to replace/rewind it but have no idea about the secondary side ratings and my best guess is that its around 15-16v on either tap / 10 Amps! I'd highly appreciate it if anyone can help with the transformer data or by providing the service manual. Cheers
@mguess
7 ай бұрын
Yes, I'm still here and try to respond to all comments. I don't think I've ever had a commenter from Egypt so welcome to the channel. I'd love to visit Egypt some day. I do have the service manual in pdf format which contains the schematic. I can email that to you if you want. Send me an email to mguessva@gmail.com and I'll forward the service manual to you.
@adelhelmy2812
6 ай бұрын
Many thanks for your response and support 👍
@hugosantos4823
7 жыл бұрын
Um amigo meu acabou ganhando da tia que morava no Eua um Jvc Rx-D205s, ele acabou me dando esse receiver. Por não ser comercializado no Brasil não encontrei informações sobre o mesmo. Sei que é um modelo antigo, mas estou afim de utiliza-lo. Gostaria de saber qual tipo de alto falante posso utilizar nele. Possui 7 canais e uma saída para subwoofer ativo. As informações contidas no manual são: Output Power At stereo operation: Front channels: 110 W per channel, min. RMS, driven into 6 Ω at 20 Hz to 20 kHz with no more than 0.8% total harmonic distortion. At surround operation: Front channels: 110 W per channel, min. RMS, driven into 6 Ω at 1 kHz with no more than 0.8% total harmonic distortion. Center channel: 110 W, min. RMS, driven into 6 Ω at 1 kHz, with no more than 0.8% total harmonic distortion. Surround channels: 110 W per channel, min. RMS, driven into 6 Ω at 1 kHz, with no more than 0.8% total harmonic distortion. Surround back channels: 110 W per channel, min. RMS, driven into 6 Ω at 1 kHz, with no more than 0.8% total harmonic distortion.
@mguess
7 жыл бұрын
I'm sure you could probably use any 8 ohm speaker. It sounds like you have a 7 channel AV receiver designed for home theater use. I do not have a home theater. I just listen to stereo music. I have used AV receivers in stereo mode for music and they work great. You just use the front left and right channels and don't connect the rest of the channels.
@hugosantos4823
7 жыл бұрын
Thank you for your help.
@garthwood5104
3 жыл бұрын
I too have been looking for the service manual for the RX-401, and I'm *very* surprised that it doesn't seem to be in any of the manual archives scattered across the 'Net. Anyone willing to upload it to one of the better-known archives like BAMA, KO4BB, Elektro-Tanya, hifi-manuals.com, hifiengine.com, vintageshifi.com or others?
@garthwood5104
3 жыл бұрын
Oh, and I've owned this model since I bought it new in 1989, and it's still going strong (though I'm sure I'm gonna need to service it on my bench at some point, which is why I'm trying to find the service manual).
@mguess
3 жыл бұрын
I have the service manual in PDF format. I'll forward it to you if you can give me your email address.
@garthwood5104
3 жыл бұрын
@@mguess Thanks! It's garth-at-telusplanet.net (replace "-at-" with "@").
@tk-ed6pe
7 жыл бұрын
das Relais öffen und die Kontakte reinigen mit feinem Sandpapier und dann mit Kontaktpflegemittel konservieren hilft und kostst fast nix habe ich schon bei mehreren Relais erfolgreich gemacht
@mguess
7 жыл бұрын
I'll try that next time. The replacement relay was fairly inexpensive.
@tk-ed6pe
7 жыл бұрын
wir haben bei uns pollin elektronik da bekommt man welcjhhe als 2 mal wechsler die überflüssigen Beinchen abgeschnitten geht dann auch kosten nur so 95 Cent Euro -:)
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