LEDs glow, fan noise is heard, but display is

Hi,

Even I am facing the exact same problem with my HP pavilion entertainment PC Laptop
1. Sometimes, on-button glows, recognizes cd-drive, fans etc.... then nothing happens, not even POST. I mean a complete blank screen. num-lock,capslock do not glow. the sound os and wireless led are orange instead of blue.

2. Some other times, it boots normally and works completely ok till I shut down or restart.

Repairman told me maybe Mother board is screwed but then if that is the case, then why should it work sometime and sometimes not? i tried to reboot it a couple of times wich worked in the beginning but not anymore...

HELP!

You can respond here or send me an email @ sabinadejong@msn.com

Please help!