Death chime and Simasimac on Mac SE/30

[pgreenland]

I've got an SE/30 which started with the same symptoms, horizontal stripes, no booting, death chime.

It's had a minor battery leak in the past, which a previous owner has cleared up.

I followed @techknight advice and found a few address lines that the battery acid had got around some of the F258's.

With those repaired I no longer get the death chime, but the screen isn't cleared either. Initially felt like a regression. If I press the reset switch, no change. If I press the interrupt / programmer switch I get the chime of death again.

Would that indicate that it had got a bit further through booting than before?

 

[pgreenland]

Progress update I discovered AppleCAT SE/30.

Sheepishly connected my working SE/30 to the dead one.
Started the tests.
Communication established.
ROM / RAM / address / data bus tests all pass.

PRAM test results in a chime of death and loss of comms with the test machine.

No activity on the RTC comms lines during this period.

Buzzed out the address, data and control lines going into VIA1, along with its connection to the RTC, all good.

Could it be a dead VIA chip?

Logic analyser probes annoying don't want to grip its legs with the floppy connector in the way....may try tacking some wires on, see if the control lines are toggled at all.

 

[pgreenland]

Update for any future intrepid travellers.

I've somehow managed to fix it.

The SWIM and ADB chips were looking pretty crusty, with lots of corrosion on their legs and a small amount showing on the tops of vias surrounding them. I suspected more broken traces, so tried cleaning the board with vinegar for an hour, while gently brushing the legs of the chips with a tooth brush every now and then. I've never washed electronics with vinegar before but ignored the nay sayers.

Attempted to clean any traces of vinegar off the board by scrubbing with washing up liquid and plain old tap water (I know impurities and whatnot....but my original ultrasonic cleaning with distilled water and PCB cleaning solution didn't help all that much)

Dried immediately with a hairdryer on max fan speed, minimum heat, attempting to blow water out from under chips and hiding in connectors.

Powered back up, to my amazement I'm greeted by a bong and eventually a disk prompt.

Booted a floppy without issue, SCSI without issue.

Passed all of the tests in Snooper.

Glad I didn't tear into it anymore.

Seems a recap, couple of traces being fixed and several baths were all it needed to get it back on its feet!

 

[imactheknife]

Surprising how that happens. My recapped se/30 worked after recap but still gave me the horizontal lines once in awhile. I took 600 grit sandpaper and cleaned simm slot contacts, reflushed board with isopropyl as well as cleaning simm slots and let dry. No issues at all now. Glad to see your board working