Print

[ried]

I picked up a Parallel expansion card and installed it in my Dafax Macintosh XL, which features both an XLerator and an LSAC. I didn't realize it at the time, but the Parallel card was missing its card stop. When I attached the ProFile's parallel cable the card shifted a little, but I thought nothing of it. I should have. Just like my previous experience with the Sun Remarketing SCSI card in a slot with a broken yellow cam, this Parallel card shifted in the expansion slot enough to short something and cause the machine to not boot. Power on, mostly dark screen with a little bit of snow-like artifacting, no CPU "pop" and... nothing. Yikes.

When the Sun SCSI card died, it took down some portion of the CPU board. Did the Parallel card kill this CPU board, and (gulp) take an XLerator with it?

Removing the Parallel card and powering up gave me an instant single beep and a dark screen. Uh oh... that's a new one for me.

I pulled the XLerator and LSAC out, then put a standard 68000 CPU in the socket. Power on and there's a screen with 19 vertical grey bars. That's... a new one for me, too.

So I swapped in a known good CPU card. Heard the CPU pop sound and the screen lit up (progress!), but POST would not execute. Just a grey screen sitting there with 3A in the title bar... not executing the full CPU, Memory, I/O and expansion card POST.

So I swapped the I/O board for a known good unit, too. After the I/O board was in, POST completed successfully. I moved the PFG to that replacement I/O board and powered up once again to confirm that, yes, POST still completed successfully.

The moment of truth... installing the XLerator onto the replacement CPU card (left the LSAC out for now). Powered on and... it worked! Whew! Reinstalled the LSAC into the expansion slot and it works, too. Pure luck.

So, because I was not paying attention to the missing card stop I have damaged a Parallel card, a CPU board, and an I/O board. This is the second time I have done this, and should have known better. Don't be me.

[bmwcyclist]

Damn! Thanks for the heads up!

[AlexTheCat123]

Oh wow, that sucks! I've heard of someone having this happen and it frying just their CPU card, but not CPU, I/O, and the parallel card. That's pretty unlucky.

Interestingly enough, I've done this exact same thing more times than I'd care to admit, but aside from preventing the Lisa from turning on until I reposition the card properly, I've somehow never done any damage to anything.

Try looking through the boot ROM to see where things might be failing, and you might have some luck with repairing things. The CPU card might be a bit tougher given that it's not doing anything at all, but you should at least be able to fix your I/O board. I've been staring at the boot ROM so much lately thanks to the FPGA project that I can't keep things straight and can't say exactly where things are failing for you, but getting the click and not having that looping CPU board error (the one that shows up when there's no I/O board) means that the keyboard VIA and SCC are probably at least partially working at the very least. And it has to be setting the contrast too, so the parallel port VIA is probably showing signs of life as well.