Recently I've tried to boot using rescue floppies and after POST the screen would flicker. I opened the case to check for loose connections. I found no loose connections but a whole lot of dust & lint on the CPU heat sink.
I removed and cleaned the heat sink and fan. Also one of my CD ROM drives had died a while back so I took the opportunity to remove it.
When I switched the P.C back on it would come to life and after about 10 seconds shut down again. Any ideas how to fix this?

Sounds like a heat problem. Can you stop the POST and get into the Bios/CMOS Setup and check the temp?
Did you verify the cpu fan is running? Did you change where it plugged in?
Did you wiggle or move the heat sink much? You may need to pull it and re-apply heat compound.

Sounds like a heat problem. Can you stop the POST and get into the Bios/CMOS Setup and check the temp?
Did you verify the cpu fan is running? Did you change where it plugged in?
Did you wiggle or move the heat sink much? You may need to pull it and re-apply heat compound.

Did wiggle heat sink a bit when cleaning. Fan is working. The machine stops before POST even comes up.

ALWAYS CHECK THE BASIC STUFF FIRST!
I finally got my P.C working again after securing the heat-sink properly.
If the clamps are not applied correctly the CPU will shut down to protect against overheating. Anyway I still had a blank monitor. When I was reattaching the moniter cable I noticed it was frayed. Only when I wiggled the cable a bit did my monitor work again.
So everything is all fixed now. :D

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.