Okay I have a Zx5000 laptop with a pentium 4 and 1.2 gb of ram and have been having problems with it lately

a little while ago the laptop kept on giving me a blank screen on boot, it would just sit there forever and nothing, but everything powered on, lights cd drives fans everything. so i found out after that that if i turn it off and on over and over again it would WORK, and if i turn it off and let it sit for about 1 minute or so it would come back on without a problem, anymore than that and the problem comes back

when i can finally get it on and put it on standby and leave it for a while it happens again, but this time its on standby with a blank screen

so a month passes of going through this crap and now it won't boot at all, the lights just come on and the fans turn on at boot then go off and then go on again, then the cd drive spins up

its like the system thinks there is no screen so it continues without the screen, but stops after the bios but you can't see anything not even on external

so i removed the processor(didn't work)
i removed the ram(didn't work)
i removed the hard drive(didn't work)

does anyone know what could be the problem, i was thinking that maybe its the lid button

i just got it on after playing around with the cpu but there is so much thermal paste on the cpu that i can't beleive it, its also rock hard and i don't know how to get it off,

its just stuck

does anyone know how to get a heatsink seperated from a cpu