Laptop all LEDs turn on suddenly when plugged but won't boot up

[pagatpatn]

Hi i have a HP Compaq Presario V3000 when i plug it all of its LEDs suddenly turns on even the DVD drive's LED but when i press the power button nothing happens it doesn't power up just nothing the LEDs stay turned on. Is it the motherboard or possibly anything else?
I also tried pressing the power button for 30 - 60 seconds with battery out and unplugged but it's still the same.
Also tried removing the RAM and HD then rest a bit then put it back still didn't help.

 

[webworkings]

If the lights are on it may well be on, just not the display. Try this...

1. Turn the laptop off (not sleep or hibernate but off).
2. Connect an external monitor to the laptop.
3. Turn on the external monitor.
4. Turn on the laptop.

NOTE: You may have to press an "external monitor" button. Could be the f4 button or a button with two monitors on it, for the external monitor to work.

If you can see fine on the external monitor, then your attached display, or the ribbon cable that connects it, are your problem.

If you can't see on the external monitor at all, or the problem occurs on the external monitor as well, then it is probably the graphics card/GPU that is the problem, which may require the motherboard be replaced.