Logic Board reworking: A Tale of Two IIcx

[Addicted]

I narrowed the final IIcx issues to the internal SCSI drive. Guided by memory dumped with TestManager and a listing of the IIcx ROM generated with a m68k-capable objdump (cross-referenced with an annotated listing of a Mac 68000 ROM found online), I found the system was very reproducibly taking an illegal instruction fault while loading the SCSI driver. The exception PC was in low RAM, and so the driver (SilverLining) on that disk looked to be corrupt; there was nothing resembling legit machine code near that PC. The internal disk on that system is being media-checked for bad blocks now. Two bad blocks right out of the gate, so, hm.

Whew! It's not the logic board!

.. and so I conclude my tales of 68K Mac restoration. It has been fun, but with VCFW coming to a musem near me at the end of the week, I've decided to send all my restores to good homes and move on. I think I've babbled so much here that I've driven everyone off of reading my logs anyway, and I do need to put my time into more recent tech for a while

 

[finkmac]

i for one appreciate the work log. always good to see the way a pro does things.

 

[Addicted]

Not sure I have earned the rank of 'pro', but perhaps you were speaking of the larger audience here

As I prep all these systems for VCFW, I am seeing a common challenge: HDDs which all through the restoration process were not part of the problem are now failing at the last moment. "NOT READY" conditions, almost every one. Some can be heard spinning up and down, regardless of how much surplus wattage the power supply offers. And I lack a SCSI analyzer (or enough channels on my Saleae) to figure out why.

HDDs, with their constantly moving parts and delicate tolerances, can experience EOL at any moment, and Murphy's Law says such problems always happen on the night before the demo. I should have started prep a week earlier...

So some of these systems will go to consignment without HDDs, counter to my Master Plan. I'll put little notes on them recommending BlueSCSIs, external disks or other alternatives. But I doubt anything other than a "take it home, plug it in, and enjoy Daleks" solution is going to sell for even $5.

And regardless of the HDD state of each system, I have never counted on every single one being bought, no matter how low I set the price.

So.. I am hanging on to anything that I might need to do a final round, a Second Revival, of any systems that do not find homes. Making CDROMs of my accumulated apps, drivers, and utilities.. keeping the CD-R writer.. hanging on my Tash20 SD/XC SC20 emulator.. keeping the ROMinator.. oh, I've used the last of my replacement SuperFloppy ejection gears.. etc. I realize I may be not done posting here, no matter my goals.

I will try to write up a few summary hints to leave for those who take up the hobby or 68K restoration.. but since (as I have said) I am really poor at writing a concise, brief summary - that may not come to pass. And I have a couple of final questions to ask the forum, which may also benefit the crowd and keep more 68K Macs running.