I want to share a solution that worked for me. Maybe it will work for someone else too.
For about two years, I've been fighting problems where my XPS 8900 would INTERMITTENTLY fail to start. It could be a Restart, or cold start (Powering On using the Power Button on the chassis).
Either the monitor would continuously display the round Dell Logo, or the display remain black/blank.
While the color of the Power Button was white, indicating POST (Power-On Self Test) was successfully completed, there was no indication of Hard Drive activity (no hard drive noise or white activity light).
Repeated diagnostics, OS reinstalls, and BIOS updates made no difference. Running with RAID-1 or without RAID made no difference.
My Operating Conditions:
Recommendations for Troubleshooting Intermittent POST/Boot Failures:
Don't know if this helps anyone or not, but with all the trouble I've gone through over the last two years, I felt the fix that worked for me should be shared.
Great troubleshooting and work. This should help not only the XPS 8900 owners but maybe other XPS desktop owners.