Okay, that gives me some hope. I was thinking about getting a good, quiet 400w supply off of ebay and hooking it up to the adapter. Something like an Antec or EVGA, with 80+ cert.

The only video I found on YouTube about this mentioned that PFC was something to look out for, but the guy was using an older XPS with a P2  instead of a 4100 so maybe there was a difference in how they handled it. Here's the vid: https://www.youtube.com/watch?v=h5wmwfsbaNM

The video at least confirmed that the P7 (or P10) connector is with all 3.3V.

As said I personally never heard of a PFC (Power Factor Correction) PSU giving issues, but that doesn't mean much, the catching fire could be true or only a metropolitan legend for all I know.

From what I know the PFC is essentially circuitry on the "high voltage" side of the PSU (AC mains) and whether a PSU has (or has it not) is (should be) irrelevant on the low (DC) voltage side, the whole idea is to transform an reactive load on the grid into a (almost) resistive one, thus old dansdata article explains it:

http://www.dansdata.com/gz028.htm

jaclaz