My dv6000 p/n GL913UA#ABC (dv6424ca) running Windows Vista won't boot. When I power up from cold the screen stays black, hdd light flashes briefly, blue indicator lights come on for 30 secs, then power cycles off/on multiple times. No beeps, no flashing of caps lock and num lock lights. I connected an external monitor but it is black too. I did a hard reset several times, tried new memory, another power adapter, removed and reinstalled hdd. Backup battery is 3.1 volts.
Any help appreciated!