PSA: Dell Uses Duplicate Part Numbers
Lesson learned. Apparently Model Number on Dell parts don't tell the whole story.
I had a problem with a Dell Precision 690 where the the tower would power up, but I would get no video. I tried everything: different monitors, both analog and digital (DVI); different video cards; different video cards in a different slot (PCI instead of PCI-E). Same result...
I made the $35 investment to get a digital power supply tester from Best Buy, which works rather well, might I add. However, in this instance, I was unable to successfully test the power supply.
Long story short, I got the model number of the Dell PSU and started my eBay trek. I found the auction that matched model numbers and specs. Within 2 days, I had the replacement PSU. I got down to business installing.