Thanks for the response @Byrd, just given that a read, looks like a neat idea.
I've looked into the revisions, it would appear that both of these are Rev 2s, as the CMD chip is labled '646U2-402' as opposed to 'PCI646U2'.
I also tried putting the internal Zip over from the dead machine to the working one. Weirdly, when I tried that, it turned itself on when i plugged the machine in and refused to chime. Taking it out again sorted it out
I just don't understand how some of you get the 2MB ROM to work. I tried everything, including multiple motherboards. I even added solder to each pad on the ROM SIMM. Nothing -- I mean NOTHING -- worked. Then Zane shipped me the 8MB version and it worked just fine on the first try. I know it's not the content of the 2MB ROM because I have a ROM-inator II programmer and verified the ROM content that way.
I have a IIci that powers up, in so far as it than fan is on and the little green light in front comes on. It doesn't chime.
I replaced the PRAM battery. I tried it with just 4 sticks of RAM, no NuBus cards and the cache card. The same.
My question is: is this simply a board that needs a recap or are there any visible signs of permanent damage?
There are signs of cap goo up by the sound chips in the upper left of the first picture.
Here are some two photos of the motherboard.
Thanks for your help
ok, good advice for sure but part of my question is the practical aspect—HOW is this best accomplished? i assume continuity checks with a meter, but is there a good guide or reference i should use, or do we all use schematics?