Sounds like dead PSU.

[.... My HP pavillion is in identical state... I wonder if it is faulty BIOS... Because all the lights go on and nothing comes on the screen... what shall i do ?

HP? NEVER AGAIN! The laptop is under warranty![/QUOTE]

Hi All, I ask for advice because I've tried all my best: The HP pavilion when power button pressed all lights (LEDs) go AND STAY on, but laptop does not boot, nothing comes on, how can i go ahead?

[/QUOTE]
hi, if it under warranty then return it or at least contact HP for troubleshooting help .

try removing the battery and just use the power plug.
dose it sound like its boot ,just not showing anything on the screen ,if so hook it to a regular computer monitor

HP is CRAP!!! I had this problem. Had the MB fixed by a shop in Miami. After all updates uploaded the problem came back. HP waited to offer a free fix AFTER the warrantee on these machines expired. So now they want $400 for the repair. I am convinced the bug is being intentionally uploaded during one of HP's "updates". HP deserves to be sued, count me in.

HP pavilion dv60000: all LEDs are on, does not boot, no video. The had drive spins time to time and the but cdrom makes noises
Hi,
I ask for advice because I've tried all my best:
I have 3 Pavillon dv60000 laptops. When power button pressed all lights (LEDs) go AND STAY on, but laptop does not boot, nothing comes on video, neither LCD nor external monitor works, but DVD drive makes periodic noises, like getting requested by the MB.
I did a hard reset and it did not helped.
I'd appreciate any clue about this matter.