Mac LC-II battery corrosion, will it ever run again?

[rubber_jonnie]

@rubber_jonnie I was just surprised it all worked with the Blue Scsi so easily

BlueSCSI is just great when you have a genuine Blue Pill.

Once I got the genuine article mine worked right away with both the Mac Classic and A5000. It's a great solution for sure.

[PhilC]

Been having a look at the other LC and it looks like all the pins that should be connected on the 68030 now are at least mechanically, just got to check them all electronically next.

One thing I have noticed is that /BERR is low, so we have a bus error being generated by one of the chips, not sure which one yet.

I did swap the roms over with the other LC and they boot just fine in that, so one less thing to worry about now.

[rubber_jonnie]

Been having a look at the other LC and it looks like all the pins that should be connected on the 68030 now are at least mechanically, just got to check them all electronically next.

One thing I have noticed is that /BERR is low, so we have a bus error being generated by one of the chips, not sure which one yet.

I did swap the roms over with the other LC and they boot just fine in that, so one less thing to worry about now.

God I hate battery damage, it's so insidious.

Good news re the ROMs though. Damn, wishing I still had my LC 475 :(

[PhilC]

@rubber_jonnie it certainly is. This is turning out to be an interesting project for.corrosion repair and certainly proves that you can never judge pcb corrosion just by looking at the pcb.

[rubber_jonnie]

@rubber_jonnie it certainly is. This is turning out to be an interesting project for.corrosion repair and certainly proves that you can never judge pcb corrosion just by looking at the pcb.

Indeed not. My A5000 needed several ICs replacing even though they, and their traces looked fine, would have had no IDE otherwise.

[PhilC]

Just to give a brief conclusion to this topic.

I was unable to get this machine to boot at all, sometimes there would be activity on the address bus, quite often not. So yesterday I decided that the motherboard would be stripped for spare parts but at the same time I'd investigate what had happened to it.

The quick answer is that the battery acid and leaking caps whilst looking fine once I'd cleaned everything up, had made its way underneath chip and capacitor pads on the board, breaking the majority of contacts between the caps and the other side of the board. Similar had happened with the SMT chips on the board.

So this Mac now works thanks to a replacement motherboard.

And in other news I managed to get an LC475 for a reasonable price with had corrosion damage once again. This I did manage to fix. The main corrosion damage was to the pins on the 68040 making 7 of them come unstuck and the CPU therefore useless. New CPU, a clean up etc and now that ones great.