Kevin,
I worked with Dell with no avail. We tried everything, Windows System Recovery Disk, Windows Install CD, receding the memory card, etc. The system would get to a point and just power down. The BIOS was the same. I change the BIOS configuration and Selection SAVE/EXIT. After a minute or so, the system would power down. When Dell gave up, I went to the Boot to Utility Partition and tried the option under Test System, Symptom Tree, and ran Cannot Boot The OS. It ran for many hours but when completed the system boot successful.
After running Cannot Boot The OS, the pass two days, I can now boot successfully tonight. However, the problem is not resolved. I believe I have an issue somewhere in the chipset that causes the system to power down. While I have the system available, what can I run to help isolate this problem?