Yet another dead(?) Power Mac 9600/300

[HunOmegared]

I recently got a 9600/300 (tested stock 300mhz cpu, Kansas logicboard, tested ram sticks /4*128MB/, ixmicro 128m8, GOOD pram batteryS, good psu, 4gig hdd, cd, zip, floppy).

Chimes, but thats it.

No video, no keyboard (no response to cmd-opt-p-r, can power on with keyboard).
I tried evertything, cuda reset, logic board reset, another CPU (Sonnet 400), ram, different videocard (fw modded radeon 7000, mac rage128pro), disconnect scsi (hdd termination jumper set, hdd last in cable - no difference when scsi cable plugged in or not) etc.

Chime comes almost immediately after i press the power button.

Without the ram sicks no broken mac sound, just chime.

Tried to get to OpenFirmware, with cmd-opt-o-f, holding down looooong the power button, but the system shuts down after 1-2 secs.

Anybody have any idea what anything can i try?

Thanks:
Daniel

 

[trag]

Try washing the board thoroughly, probably with 91%+ isopropyl alcohol. The caps may have leaked enough goo to cause a short somewhere or may have eaten a trace.

If the former, while the caps still need replacing, washing the board may get you to a workable state for testing.

If the latter, washing won't help, but you'll probably want to eventually.

Of course, the board problem may be completely unrelated to the caps.

 

[PPC_505]

For what it's worth, my Tsunami 9600 always needed a "running start" no matter what media I used. Had to Power On > Chime > Power Off > Power On again and it would come up correctly.

 

[This Does Not Compute]

This is a typical symptom of a dead PRAM battery; the "jump start" trick (turn on, off then immediately back on again) was a common one back then.

 

[OJmacman]

I recently got a 9600/300 (tested stock 300mhz cpu, Kansas logicboard, tested ram sticks /4*128MB/, ixmicro 128m8, GOOD pram batteryS, good psu, 4gig hdd, cd, zip, floppy).

Chimes, but thats it.

No video, no keyboard (no response to cmd-opt-p-r, can power on with keyboard).
I tried evertything, cuda reset, logic board reset, another CPU (Sonnet 400), ram, different videocard (fw modded radeon 7000, mac rage128pro), disconnect scsi (hdd termination jumper set, hdd last in cable - no difference when scsi cable plugged in or not) etc.

Chime comes almost immediately after i press the power button.

Without the ram sicks no broken mac sound, just chime.

Tried to get to OpenFirmware, with cmd-opt-o-f, holding down looooong the power button, but the system shuts down after 1-2 secs.

Anybody have any idea what anything can i try?

Thanks:
Daniel

My only thought is that this "on-off" try and try and try situation would happen IF the PRAM battery(s) on many Macintosh declined below a certain voltage. This is only a hunch but some of my Power Macs don't even like 3.4 volts let alone the rated 3.6Volts. It has happened to me with PRAMS @ 3.5 volts and the Mac was not happy. Bought brand new fresh PRAMS and my Fluke tested them at 3.6Volts and they fired right up. I am old but I am still devoted to my previous labour of love using what are now considered vintage Macintosh. I hope my suggestion might help?