I am now working on a Mac IIci.
All I get when I plug it in is a green blinking power and HD LED's about twice a second. The fan is spinning.
I have repalced the battery with a new one. There was no leackage from the orignal battery.
I have reseated all socketed chips.
I pulled all cards except video. No change. The HD does not spin up.
the PSU is an Astec unit AA 15831, apple part # 614-0004. I open the PSU and it was not very dirty. All this caps looked ok. the small riefa caps were not cracking.
The whole system was very clean, and appears to be littled used.
Sugestions on what might be wrong with this mac??
Have you recapped the logic board?
I'd start by metering the output of the power supply. If you aren't getting the right voltages nothing else matters. It could even be causing the hard drive not to spin up if you aren't getting enough power. The other likely problem with many of the hard drives out of that era is "stiction". Quantum drives in particular suffered frequently from that, where the heads would stick to the platters and the drive won't power up. Sometimes giving the drive a whack in the right spot will temporarily make it start up (not too hard though). Usually at best that is a short term solution, just enough to get your data off.