i bought a HP NC6400 off ebay that was for parts or repair and repaired it. i have replaced the case bottom, motherboard, ram, hard drive, heat-sink, keyboard, LCD, inverter and screen bezel. there are also 5 screws missing out of the bottom of the case(waiting on replacements)but after putting this laptop together every thing works fine except this one random issue.
I'm calling this a short cause of whats happening. the screen goes out(light and and picture shuts off)the power stays on, and the mute button on the media board lights up. i can reproduce this if i pick up the laptop, or flex the case bottom (pick up one corner) while its sitting on a desk or table. i have also had BSOD show up a couple of times. i should probably mention that the first time turning the laptop on after rebuilding it started to power up and then started a constant reboot cycle. i pulled the system apart again and checked to see if the mobo was touching something on the case bottom, which was and got fixed. since then i have had the system apart once more to check for things touching which was what i had thought was the issue and i even covered the metal places that i thought might touch the mobo in the wrong places(spots that screws didn't go to)with anti-static tape. upon reassembly i changed the position of some of the case screws to help keep the laptop from flexing as much, and it seems to help, but i still have the same issue.
now could this issue be the missing screws in the case, or am i missing something. since this it the weirdest thing i have EVER seen or experienced i am at a loss as to what to do. any one with any ideas would be more then appreciated