Quadra 660AV tinkering

[BigBadBiologist]

I've been working on a Quadra 660AV that had heavy capacitor damage. (good reset and clocks on main chips, no chime, seems like CPU locks after a few cycles)

In the process, I've been documenting stuff like voltages, signal descriptions, and resistance to ground for a good board. All my info is on this spreadsheet in case anyone is in a similar situation (there will be updates as I continue work).

660AV documentation

docs.google.com

I also have some info about what happens if you remove various chips from the board:
all onboard RAM- chimes normally (no death chime!), but no video. can add SIMM to boot normally
U51 / DSP- will chime and boot fine (possible hang if SIMM installed)
U52 / NEWAGE (floppy controller)- will chime and show gray screen, but no cursor or flashing floppy
U20 / CURIO- will chime and show mouse but waits indefinitely (mouse works)(Y4 does not work without curio)
U55 / MEMCTL- no act (TEA high, BERR float/low)

 

[RetroViator]

This is a great level of detail that will help others. Personally, I’ve not had the discipline to document my knee jerk reactions, back and forth testing, and head scratching approach to my repair work.

Keeping a lab book is a good idea. I would like to come up with a way to conveniently dictate as I go and then clean it up later.