On a desktop you debug by pulling parts. On a laptop it's harder.
(1) what sounds do you hear when you power up? Is the CPU fan running? Are there any beeps? (if beeps then google 'beep codes' then check your manual for what the beeps mean).
(2) Do you have anything in the USB slots you can remove. Can you remove hard drive? Can you remove memory? Can you remove network mini-pci card? Etc. Pull parts until the laptop lights the screen up. "Removed battery, HD, memory cards and no change" yes, only more.
(3) Can you connect an external monitor? Your LCD video may have failed.
(4) Is there a reset sequence in your manual ? (you did the right thing removing power and battery and waiting, sorry that didn't help).