My XPS 8500 from 2012 will not POST. Fans spin up briefly, then stop, then spin, then stop, etc. No beeps. No connection to the monitors on any port. Keyboard and mouse do not light.
The problem seems to be related to an external USB hard drive I connected to the top panel. If the computer went into sleep mode with the drive connected, it would not wake correctly, and would restart in safe mode. If I unplugged the drive before the computer went into sleep mode, then no problems. The last time, I accidentally left the drive connected, and now the computer will not boot at all. It will not POST.
MOBO light is solid amber. Power button is blinking amber. No beeps. Light on the back of the power supply is steady green. When I power on, the fans spin for 1-2 seconds, then stop. Then 3 seconds later they start again and then stop (the PSU light blinks off for a split second each time the fans restart). And again and again. It would continue interminably unless I unplug the computer. All of the fans spin and stop in unison (unless I disconnect them from the PSU/MOBO): the fan on the back, the fan above the heatsink, the fan on the video card, and the fan in the PSU itself.
I have tried the following:
- hold power button for 15 seconds, 30 seconds, etc., and retry. No change.
- disconnect each and every component from the MOBO, one by one, then together, and in every combination: hard drive, optical drive, video card, both RAM chips, the top and front USB ports, MOBO battery, memory readers. I have turned on the machine completely bare and the exact same thing happens.
- plugged computer directly into wall outlet without a surge protector. No change.
- reset CMOS per the manual. No change.
- every conceivable combination of the above.
I have not found a suitable power supply to swap in to test if it's the power supply, or the motherboard. I have not unseated the CPU, but have done everything else I can think of.
Any ideas?