Thread: PC POSTing only 50% of the time.

Hello everyone,

I've recently been having problems with my laptop, where everytime I turn it on, it only POSTs sometimes (yes, post, not boot). When it does POST, everything works 100% perfect stable no problem etc. When it doesn't post, all I get is a black screen (not even turned on), the fan turns and the LEDs turn on, but that is it. No HDD activity, no Booting, no Windows etc. NOTHING.

The problem has gotten worst and the PC practically never POSTs now. It being out of waranty, I oppenened it up and removed almost every non-vital part of it, took the occasion to dust the motherboard etc.

Right now, the PC is only basically only a motherboard attached to the screen. I'm turning it on with a screw driver:
-Motherboard
-CPU (AMD TURION 64 X2 TL-50)
-Heatsink
-Screen
-NO HDD
-NO Keyboard
-NO CD drive, Network adapter, USB adapter
-Memory: With & Without (see below)

As of right now, the PC posts with an almost perfect 50% ratio. What's even weirder, is that it alternates, turns on, doesn't, turns on, doesn't etc.

I can even garantee that it is not a memory problem either, as even without memory, the PC POSTs 50% of the time (But I of course get a BIOS error)

Does anybody have a clue what is going on? I'm willing to try somthing more drastic like taking out the motherboard, cleaning the CPU pins and stuff, but I don't really think that would help, especially since the comp is stable when it does run.

What could be causing a computer to POST 50% of the time, especially with such a 1:1 ratio? Any thoughts? I'll take any suggestions or ideas.

PS. My BIOS is up to date.
PS. Laptop is HP Pavilion dv2003ea

I haven't taken the time to check each capacitor individually for burn marks, swelling etc.
But then again, (and unfortunately, I'll probably end up saying this for everything), if it was a faulty capacitor, I'd probably have some stability problems when the computer DOES post.

I get this problem regardless of power source (battery, outlet, both). I also tried the good old 10 minutes power down and discharge, but that did not change the results at all.