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For starters, resoldering the joints on the flyback transformer and all of the connectors might help.

C33, C37, and C38 all appear to be RIFA line filter capacitors, and those don't affect the operation of the computer when they fail.

Found it here. Admittedly being a wiki it could definitely be wrong, although I've always found this one to be pretty accurate (bit of a keyboard enthusiast myself). Do you have a serial number/date of manufacture for your keyboard? Given the madness that was usually going on at Apple around...

A bit of googling about reveals that the original Apple Keyboard/Extended Keyboard (M0115/0116) were released in 1987 to match the Mac II and SE, and the Keyboard II was released in 1990 to match the LC.

I can confirm the EGRET causing issues too; on the LC series they usually sit in a nest of caps and all the leads get corroded. I've been able to get an LC II to go from a black screen to a '?' floppy screen by reflowing the leads before.

It could be the TDA7052A itself that's faulty.

Sometimes SEs and SE/30s (with which the IIcx is closely related) have the issue you describe when the Bourns filters go bad. The IIcx doesn't seem to have the same kind of filter found in the SE/30, although it does have one at RP13 right next to the external floppy port. Maybe that part is...

That plastic bar isn't stock. It's hard to tell, but it seems that the tabs for some of the SIMM slots have been snapped off, so I'd guess the bar is there to hold the SIMMs in place (and maybe the RAM not being seated correctly because of this is part of the problem).

Check for continuity between C2 and R3, and between R3 and the internal speaker jack. Run patch wires between them if there isn't continuity to fix the sound issue. As for the chimes of death, a good starting point would be to make sure your RAM is good, if possible.

I think the 6360 and 6400 are also Alchemy-based.

Following the traces is probably your best bet since there isn't an analog board schematic to show what's connected where. TDA7052A could possibly be at fault too, it's hard to tell for sure. Just wondering, what are the voltages at pins 1 and 4 of the TDA7052A (not sure what exactly they're...

Not sure about this, but wouldn't you at least get a chime of some sort regardless of if the NuBus controller is good? Are all the voltages from the power supply good?

I'm not very familiar with the Color Classic, but I'm fairly certain amplification is done on the analog board since there's an amplifier IC (TDA7052A) next to where (I believe) the speaker connects.

Probably an issue with the amplifier then, which as far as I can tell is on the analog board. Have you recapped the analog board yet?

I was recently able to buy my dream PCI PowerMac, the 8500! It works great, although I can't for the life of me figure out how to use the AV Capture Card. My first question: Is the television connected to the composite video output supposed to mirror the monitor attached to the Mac's DB-15 port...

Have you tried plugging some headphones/powered speakers into the computer and seeing if the sound from them is audible?

No problem  :) EDIT: One more thing I should mention is that when the oscillator is installed, make sure the oscillator's metal shell isn't touching the wire.

It's hard to tell but I'm not sure those two vias are the ones connected by that trace. I'd use an x-acto knife or something similar to scrape away the soldermask covering the trace, clean with IPA, tin the trace, and solder a wire on each side to jump over the cut. Don't worry about making it...

That may actually be the problem: Trace on the bottom is severed, and the two on the top are suspect.

Hmm. You mentioned that you broke a leg off the old oscillator; I wonder if it's possible the through-hole for it was damaged too, resulting in loss of the clock signal to some components (unless it was broken off after it was removed from the board in which case disregard this)? Also wondering...