I've finally scored a room to set up my crusty old gear in. Most of it has been in storage and needed dismantling and cleaning. Thought Id give my PC a good clean to since the internals were very dusty.
The CPU fan and heat sink were fairly dirty so I removed them only to find more dust on the cpu and its clamp, so I unclipped it, removed the cpu, cleaned every thing and put it back together.
It wasn't until the next day that I powered it up only to find the thing rebooting a number of times before finally starting windows.
The reboots were actually power down cycles occurring just after the post screen. No series of warning beeps no problems detected in windows and the bios didn't seem to indicated anything either.
A closer look revealed only half of the installed memory showing up. I've only got 2 mem modules with six slots. When I originally built the thing I remembered there were only certain slots you could use. I had removed them during the clean up but was sure I had placed them back as I found them.
After consulting the manual I found they were in the correct slots. It also said that if you only had one mem module either one of these slots could be used. After trying various combinations I found that both modules were OK but slot 2 was U/S.
Pulled the motherboard out and stripped it, began a visual under magnification, checking contacts on the slot in question, flipping it over and closely examining solder joints... nothing.
Turning my attention the cpu socket I noticed one of the fingers slightly out of line with the rest of them. It looked as though it would short with its neighbour with the cpu installed. With the finest tweezers I had I gently bent it back into place, reassembled it all and it worked!
It was at that stage I remembered the cpu slipping from my hands and onto the pins edge first from a height of no more than 10mm. I looked closely at the pins and they looked ok with the naked eye but clearly not
Attached are some pics. The socket, a close up and the pad side of the cpu