PC2002M No sound and gets really HOT!!!

[Sound Dragon]

I had planned in running two PC2002M's as Mono blocks to feed a pair of JBL 240TI's! But it was not meant to be. My older and previously working just fine Amp decided to output no sound even though the meters where moving to the music. I am embarrassed to say that the other amp and speaker was working so well that I did not initially notice the missing channel.

When I went to investigate what was wrong I noticed that the non-working amp was really hot but no thermal light was on and besides the temperature and lack of sound nothing else seemed amiss. I Checked to make sure all the connections where done right as per the manual and that the switch was set to Mono. I than reconfigured the set up back to stereo which was How I last used it and I was still not getting any sound and the clip lights would come on intermittently.

I will be looking for a tech to look into it shortly as I love this amp and really want to keep it for a long time. It has a lot of character and has led a hard life but it was in great internal shape when I got it here on AK. Any Ideas would the issue could be? thanks for any and all theories.

 

[Sound Dragon]

Is this amp particularly difficult to repair? A few techs have already declined to even see it without really getting to know the issue. The one that agreed to take her in has a poor reputation and I will not send my amp to a place with a bad rep.

 

[miklemke]

It's actually one of the easier amps to repair. The parts are available and it disassembles easily.

A typical problem with them is the Sony glue that corrodes various components and solder joints.

 

[Sound Dragon]

Found a local tech who is willing to at least put her on the bench so thats a positive step. Is the yamaha forum always this empty.....feel like I am talking to myself here. Well I guess if nothing else, I will keep a log here in case another non tech person comes along with a similar issue.

 

[Sound Dragon]

Thanks, was getting kinda weird in here talking to myself! Amp is kind of special to me as it has a little history in the AK community. It belonged to Aker specialidiot who showed me a lot of kindness in selling me this Amp. It has been with me for a few years and has sent many a worthy opponent amp packing.

a refresher for the history buffs here; http://www.audiokarma.org/forums/index.php?threads/in-the-pc-2002m-owners-club.349657/

and here; http://www.audiokarma.org/forums/in...a-pc2002m-ghetto-re-lamp.361596/#post-4538426

It's actually one of the easier amps to repair. The parts are available and it disassembles easily.

A typical problem with them is the Sony glue that corrodes various components and solder joints.

 

[SoCal Sam]

Is the relay clicking? Meters moving but no sound?? IIRC, there is a mono-stereo switch on the back panel that can lose signal. Clean and work switch. Hot running is likely too much Bias current. Adjustment is relatively easy with meter. It should run cool to the touch. Be careful; as always.

 

[Sound Dragon]

So the Amp does click when it is powered on after a few seconds. The protection lights turn off and then the meters start to flicker as if it was playing music. I am loath to turn it on again until it get on a techs bench. I plan to drop it off to the tech tonight and it will be a few weeks before I see her again.

 

[rottalpha]

So the Amp does click when it is powered on after a few seconds. The protection lights turn off and then the meters start to flicker as if it was playing music. I am loath to turn it on again until it get on a techs bench. I plan to drop it off to the tech tonight and it will be a few weeks before I see her again.

if there is a relay in the output path, I woul suspect that would be the culprit.

 

[Sound Dragon]

I will get an update on Monday from the tech. I will pass that along, thank you.

 

[mech986]

Any update on whatever happened to your amps? Likely a bias problem on one or both channels, but also problems with the mono-stereo switch, or a bad single channel which throws off the mono setup could be the culprit. Also, were you sure of the wiring of your speakers?