Thanks for the response michaaa62

Yes, the battery is fully charged. I tried to boot with the keyboard ejected but Multiboot is not showing anymore - just the Nokia logo with the LED light not blinking (which I think is white or blue). Then after awhile, it just shuts down on its own.

Ah. Will try to do flashing only the kernel of the firmware image. The firmware image is the one that has the word "combined" right? That would be wonderful if I only need to flash only the kernel since I have files in my N900 that I don't have any backup. I'll only get to flash when I get home (around 8 hours or so from now).