Compaq Presario CQ62 fails to boot

Hi, a relative of mine owns the Compaq Presario CQ62 in question, every now and again it fails to boot, until you do the power button trick,
(As in, remove battery and AC Adapter from laptop, hold power button for 1 minute, and then plug in the Charging Cable into the laptop to press the power button).
It works for a few days allegedly, however I'm stumped and am debating if it's the battery, the CMOS Battery, or something related to a direct short to ground somewhere, to which to my dismay I don't have any equipment for.

Any help in this would be appreciated, since I do not receive a BIOS blink.