Adcom GFA-585-known issue guide-Needed

[irsmonitor]

I have the 585- appears to have the leaky cap syndrome-
I found a guy that repairs amps, but he has never worked on this particular one-
its the only chance I 've got- I have explained to him it appears to be a known issue and others have successfully repaired it on this forum. he tells me if I can get him all the info from here he will attack it from there and double check it and use the recommended replacement parts etc.
the trouble is, I do a search for " Adcom-GFA-585, and all I can find is people saying there is plenty of documentation in here about the issue and how to fix it , yet all I can find doing various searches is people talking people out of doing it themselves or "do a search- I am not finding the info he will need to do this successfully. He is experienced and a local Amp repair guy that has worked on literally thousands of other amps-
I prefer to give him info on this exact amp and others successful steps that he can follow, I am even going to let him use my ultrasonic if necessary-
CAN anybody point me to the INFO to give him. I want this done in the typical manner and point him at the success oriented information.
try to keep in mind- I am at this forum because it is DO it yourself and trying to make use of others success as opposed to sending it off to new jersey for 500.00
if it fails and cant get it fixed - who cares- I am willing to take that chance for 125.00 bucks he agreed to do it.
please - I know the risks and I am at the point where it is no good the way it is- so this is the only chance I have or throw it away. it pops when turned on- and voltage is going to the right channel speaker output- and that just started- I know it will be difficult- that is not necessary to mention. I can see everyone thinks this is imposible to repair- its a paperweight right now, and if I gamble 125.00 its worth it. it may end up in the trash I don't care. if it ends up that way. but I want to give them a shot.!
Thanks in advance

[gootee]

Here is a VERY good GFA-585 "leaking capacitor repair" thread, with LOTS of details. Walt Jung, who was a member of the GFA-585 design team, even posted, several times, with some technical info. Good luck.

Speakers for Adcom GFA 585?

Cheers,

Tom Gootee

[irsmonitor]

thanks buddy, I have the resources locally to arm someone with necessary info to repair this successfully, couldn't find anything but, "don't do it , you aren't smart enough, send it to me." whats the point of DIY if you aren't afraid to give it a shot. it's mine, if I can't do it - I just find someone that can, no matter how bad it gets. it doesn't function correctly, the most I will do is not fix it- who cares. it's not like it is not been covered before- my boards are barely damaged if at all, I don't even see leakage to be honest, but I thing identifying and replacing them cannot hurt. thats all I wanted to do. after that, maybe find someone to do the adjustments . I don't have a scope anyway =anymore.!
again thanks for pointing me in the right direction!
P

[gootee]

No problem. I have a GFA-585, too. I don't think that mine is leaking yet but I am going to replace the caps.

I removed the top cover and with a good light I can see the two small brown-colored ones, installed on their sides, near the rear center of the unit. They're near the rear edges of the two vertically-mounted input boards that are mounted near the middle, in the rear.

I will just replace all of the small electrolytics in the whole unit, while I'm at it.

Good luck,

Tom

[Apex Jr]

For those interested I have Adcom 22,000Uf 100V computer grade
caps at $23.95ea 2 1/2" dia 4 1/8 Tall picture here: http://www.apexjr.com/images/AdcomCap.jpg

[irsmonitor]

Ok thanks for the input.
just to be clear, here's a picture with arrows pointing at all the caps on the input board- the two that are missing, I pulled out and tested
Inspection revealed ONE leaky cap- that tested bad, just to be safe -
is everyone basically agreeing that it is just better to replace all the caps - I mean, "all the ones that I have red arrows pointing at?" or just the brown ones?
I bought 8 of the brown 25v 220mF ,which was what was in there originally. that do not exist in the picture here- they were smaller in size, but same imprints on them, - so the guy at the electronics store said they were the same thing just not to worry about the physical appearance-

OR- is there known good ones to replace them all with-
I am not trying to rebuild this amp just get it functioning would be fine, if upgrade is as easy as replacing some parts thats fine I don't want to get into modifying it.
After that, do I send it over to someone to adjust the dc-offset or is that simple enough to do with a meter and a small screwdriver on the pots at the top? or is it possible that won't need any adjustment after replacing caps?
the unit works, its not like it exploded or anything- I' just noticed it had an issue, so here I am.

[irsmonitor]

stupid question, but, is this good to have extras of- do these blow up on people regularly?
I might be interested

[gootee]

Yes, just replace all of those. I would also replace all of the other small electrolytic caps, everywhere in the amp, while you're at it.

I would use caps rated for 105 degC instead of 85 degC. Type of caps shouldn't matter too much. I think someone said Panasonic FA would be fine. I'll probably use something like Nichicon UHE series, from mouser.com.

They should not blow up regularly; maybe every twenty or thirty years or so, they will need replacing.

I don't think that replacing the caps alone should require resetting any adjustments.

The main thing is to measure the DC Voltage across each set of speaker terminals. It should go to < 0.030 Volts (30 mV) within ten seconds or so after power on. If it doesn't, then you will need to clean the boards and components per the previously-linked thread.

There is a free downloadable service manual at, I think, HiFi Engine, in case you ever do need to do the adjustments.

Cheers,

Tom

[gootee]

Originally Posted by Apex Jr

For those interested I have Adcom 22,000Uf 100V computer grade
caps at $23.95ea 2 1/2" dia 4 1/8 Tall picture here: http://www.apexjr.com/images/AdcomCap.jpg

Thanks, Apex Jr. I may do that if I ever get around to testing the ESR of the ones that are in there now. Are yours new? Are they recently manufactured?

[irsmonitor]

Thank you so much for the info- I'll clean the boards just to be safe at this point- you are the man!