Really weird issue (sorry for the length). Have a Dell Server plugged into an APC smartups. A couple of weeks ago, it wouldn't turn on. I reseated the dual hot-swappable P/S and one came on the other did not (red error light on front). Thought it to just be a bad P/S- ordered a replacement. Next morning, server is off again. Tried to reseat the P/S, did not work. Contacted Dell "Eneterprize Chat". They suggested the Power Distribution Board. Ordered it. Installed it with two new P/S's. neither worked. Put original PDB back in and one P/S worked, one didn't. I even moved good P/S to top and bottom slot to test, worked in both slots. Next morning, no power. moved p/s to top slot and it came back on (but not on bottom). contacted Dell Chat and they said, must be the motherboard. Bought new motherboard, put it in and tested with another power supply. worked for a day and then no deal. contacted chat and they suggested "Environmental Issues", so I have currently moved the plug from old APC to new. Old APC did have an additional server running on (but it had been there for the past three years running together just fine). I have no idea what to do. i am waiting for my new P/S to come in before I let it go over night. Currently I am logging in remotely to shut it down after backup is complete. Anyone seen something like this before?