I've got a 5 year old ASUS, Windows 7, 64 bit laptop.
- When I Press the power button, the buttons green light turns on.
- The display stays black, no display, not even a flicker.
- The fan does not turn on immediately, but after a few minutes starts spinnning.
- The CD Rom drive clicks once.
- I can hear the HD spinning.
- Pressing Caps lock does not turn on the CAPS LED.
Recently, I left it on for about 36 hours, then noticed that it was at the desktop. As long as the laptop was left on and prevented from hibernating (a few days), it worked great.
After it lost power, we left it on for 2 days, no display. Tried rebooting, again and again, days go by... nothing.
Yesterday, turned it on and noticed about 2 hours later that the desktop was displaying.
- I've tried swapping out the RAM, with known good RAM.
- I've tried swapping out the HD, with known good HD.
- I've taken out the CMOS battery, left it out, and replaced.
- I've verified the CMOS battery has correct voltage (3v).
- I've tried plugging an external monitor into the VGA port to verify it is not a display issue. No display on external monitor either.
The only thing left I can think of is a BIOS issue... but how to continue troubleshooting?