Adcom GCD-600 No analog output

Schurkey

I have several old Adcom GCD-600 5-disc CD changers, one of which has a defect.

It plays fine through the digital output; the laser is reading the disc properly. Problem is that there is zero output through the variable analog outputs; and zero output through the fixed-level analog outputs. Worked fine, shut it off. Come back a week or two later--and it's dead.

There are several fuses on the circuit board; they all test good.

Thought I had some damaged capacitors; there was ick on the circuit board; there was also ick on the side of the caps. But after removing the old caps, it seems more like a hot-melt glue than electrolyte. At any rate, I cleaned off the circuit board and installed new caps of the same values, but still have no analog output.



Common problem to lose the analog output? Ideas on what to check next?

ben62670

Did you test all the fuses? Also the caps are polarized.
Ben

Schurkey

ben62670 wrote: »

Did you test all the fuses?

Schurkey wrote: »

There are several fuses on the circuit board; they all test good.

Unless there's a fuse hiding somewhere else, yeah, I tested them all. The fuses are grouped right next to the two suspect caps.

ben62670 wrote: »

Also the caps are polarized.
Ben

I put the new caps in with the stripe on the outside facing the same direction as the original ones. The circuit board under those caps looks fine; and I don't see any "obvious" bad solder joints anywhere on the board.

ben62670

Unplug and plug in the connectors. The analog section runs off a separate transformer. The power going to the analog board should read +12/0/-12vdc it may be as low as 6vdc or as high as 15vdc.

devani

make sure the trace is not open...and how did you clean the board??

I could check my GCD-700 for clues but not this week..

headrott

Was anything in the player (or the player itself) overheated at all? Also, what made you think that you damaged a capacitor?

Greg

Schurkey

ben62670 wrote: »

Unplug and plug in the connectors. The analog section runs off a separate transformer. The power going to the analog board should read +12/0/-12vdc it may be as low as 6vdc or as high as 15vdc.

Appreciated. Are you saying I should find the power connector and check the connector for voltage?

Popping "all" the connectors apart and re-seating them sounds like a simple enough thing to do. I'll try that later this week. At this point, it's all back together and being used as a transport only, the Pre/Pro is doing the A/D conversion.

devani wrote: »

make sure the trace is not open...and how did you clean the board??

The actual copper traces look beautiful. I scraped the goo off the board, and then cleaned that area with soapy water on a q-tip.

devani wrote: »

I could check my GCD-700 for clues but not this week.

The GCD-700 was made in a different factory; and the D/A converter and filter chips are different--so I don't know how much of the circuit board would be the same as the 600. I suppose they share the analog section of the board, if not the digital section.

headrott wrote: »

Was anything in the player (or the player itself) overheated at all? Also, what made you think that you damaged a capacitor?

Greg

Bought it used; no telling whether it overheated prior to my ownership. Has always worked well in the year or two I've had it--up to the point where it suddenly died.

The top side of the circuit board had a hardened, slightly sticky goo on it as seen in the photo in my first post. The sides of those two capacitors had the same goo on them. Funny thing is, I'd expect the capacitors to leak electrolyte from around the leads; or directly out the bottom. But this crud is stuck to the sides of the caps, and the area of the circuit board around the capacitors, but not (directly) under them. My thinking was that since I was ordering caps to do the crossovers of my speakers, I'd just order a couple of replacements for the CD player at the same time. About two dollars for the pair.

In hindsight, perhaps the goo was NOT electrolyte; and there wasn't a pressing need to replace those two caps. But what the heck, there's two new caps in there now.

Thanks, guys. I appreciate the assistance.

ben62670

You got it. The connector on the bottom right looks like it would be the analog ps.