Had a look at the cpu connectors since a few months back I was trying to use a quicksilver 933mhz cpu in the digital audio but wasn't successful. I now see why.
Looked at the cpu to board connectors and found one of the connector prongs was bent- out of place. Easy to find - just shine a torch or light at the connectors and there will be a difference in the reflections of light than the rest of the prongs. With the magnifying glass I still couldn't see clearly - so I had to do it with photos to show me the results of what I was doing. I made one mistake and moved a prong next to the one I wanted - but with a bit of patience the bloody job was successful. I have the computer running in macos9 again at last. Had to disconnect power cord, take out battery and reset PMU. It still showed the same symptoms until I did that.
Anyway have a look at the photos below.