powermac 9500

[imactheknife]

recapped a 9500 that had slight battery leakage. it killed the memory chip, but slot looked ok. After recap, she bongs, display comes up fine, and eventually a slow flashing question mark. I dont get the question mark when I have floppy or SCSI plugged in. If my blue SCSI is plugged in, I can hear it make noise as the logic board is accessing it but still no boot, or question mark. Any ideas on this one?? so many projects..

 

[trag]

Are you saying if you just plug the floppy drive in without a disk, the ? never appears? Same for SCSI?

If that's the case, I'd check for damage around Grand Central (343S1125). Or in the traces that connect it to Bandit (343S1120). Grand Central is a PCI device. SCSI and floppy control are both through Grand Central. SCSI is further controlled by CUDA, but the floppy drive is controlled by a different chip. So the thing they have in common is Grand Central and everything upstream from there.

But video is working, so the upstream stuff -- PCI and points north -- must be working. So I would think Grand Central is the place to start.

BTW, Bandit is the PCI controller. Oh, and don't neglect the PCI Arbiter chip. Everyone focuses on Bandit as a "PCI Controller" or "PCI Bridge" but it is not complete without an arbiter chip. Can't remember hte part number on the Arbiter. It's a little square 28 pin PLCC chip. Something like 341S0181 or some such. It'll be near the PCI slots and there are two of them -- one for each bus.

Is you video card in the upper or lower three PCI slots? If the lower, then video working, doesn't mean that Grand Central's Bandit is working. Grand Central is on the upper PCI bus. Slots 1, 2, 3.

 

[imactheknife]

actually ,I took board out, cleaned and scrubbed gently with isopropyl and rinsed with distilled. let dry over night. next afternoon, fired her up, and all is well! she works great.

 

[trag]

actually ,I took board out, cleaned and scrubbed gently with isopropyl and rinsed with distilled. let dry over night. next afternoon, fired her up, and all is well! she works great.

That's great news! Good job.

 

[imactheknife]

yeah made me pretty happy. Other question you may know or can help. I recapped an extremely clean 840av. She chimes, can hear SCSI working, after 5 seconds or so after chime, get some melody, or death chime. obviously nothing on screen. This board worked perfect before. Is there something I overlooked? Thank-you if you can help. Mark

 

[trag]

Hopefully someone else will stop by to help. My knowledge of the Q840AV is almost purely theoretical, unfortunately. I have a couple of boards from which I've removed the caps and cleaned the boards, but haven't gone any further, like replacing the caps and testing them.

They worked when I put them away years ago. I didn't test them before starting the recapping process. I was doing a literal pile of other boards and just had a week or two of massive capacitor removal...

 

[imactheknife]

quadra 840 is alive and well. Checked some pins grunge on some ic chips..fixed that