Heavily distorted output on all channels/mix

[midipuppies]

Just picked up a busted EIII and here's what I got so far:

1: All outputs are distorted and fairly quiet.
2: Sample RAM passes tests.
3: All voices are exactly the same. (No particular one acts/sounds different when enabled/disabled)
4: Re calibrated Volume slider etc etc.
5: All cards/cables seated firmly.

What do you think?

J
 

[dr.c]

Why don't you load a non distorded sound ? 

Okay... sample silence and play it. What is the result ?

[midipuppies]

Hi Doc, I sampled silence and I got ........ silence. No distortion, just a very very faint click that I could barely hear.
What do you think?

Thanks, Jay

[dr.c]

Sorry, I was away... In jail... Na... jocking... 

Can you sample now a clean sound ?

I tought you would have guessed the next step by yourself... 

[midipuppies]

Hi Doc. Yeah I was in Jail for a while. I killed a Frenchman.
How's the snow over there???

Anyway, anything sampled in has that same distortion. Any idea what is broken?
Should I think of it as a parts machine now?

Jay

[dr.c]

Can you put somewhere an example of the distorded sound so I can hear it ?

There, about the snow, but its in Ukraine, where I was lately...

[midipuppies]

Doc, I took the EIII apart and found a few things.

1: I found corrosion and pitting on the gold contacts on the micro-controller card.
2: The two output cards were REALLY dirty near the Curtis Chips.

So I cleaned and re-seated EVERYTHING and now I have nice clean sound, but ONLY on the individual channel outputs.
WTF???
Nothing on Left or Right/mix outputs. Just dead silence. Nothing at all.

Any ideas? So close now!
I don't know if I put the two voice cards back in the same order, but I don't think that is relevant to this problem.
The flat cables (ABCD), could they be the issue? I wiggled them and still got nothing.
Jay

[dr.c]

Hello ... I was at the hospital with a heavy heart problem.

Here I am, back in town ! 

Okay, there are four flat cables (20 pin) wich go from the channel boards to the output jack board. The leftmost cable is cabe "A", wich as well transports the +5V to the jack board. Sometimes, its defevtive, so unplug the connector from cable "A" and put in back in place. Maybe it it will fix the problem. These cables and connector crrimping ias a crap, its a shame, I used to replace them all systematically on every machine.
If there's no success, send me an email

[Elmbeatz]

Hello ... I was at the hospital with a heavy heart problem.
....

Hey Doc!

If this is meant seriously - PLEASE - take good care of you!
You only have one heart...

Glad to have you back here!
Greetz,
Elm.

[midipuppies]

This issue was solved. Some issues that I found and corrected and some that were completely out of my league. That's where the good doctor came in.
So, The main reason that the output was so distorted was due to some greenish powdery looking corrosion that was on the contact pins on the controller card. (the top one)
It looked as if there had been liquid on there in years gone by. I was able to clean it off with contact cleaner, a picking tool and a special wire brush tool.
The contacts were very pitted after the corrosion was cleaned and I was worried that contact would be intermittent after the cleaning.
After I put everything back together, (I checked/cleaned all cards after I found the first one), I had clean sound on all 16 channels, but nothing on the mono/stereo outs. I do not really know what caused that problem, but none the less, it turns out that the +5Voltage on pin 8 on IC3 on the jack board was not there as it should be. After restoring power to that IC, everything was fine.

[dr.c]

This is nice !!!!

[micromoog]

@ dr.c: Little bit late, but i'm also glad to see you back here.

best wishes! Stay in health!