Mysterious failure

[Tygur]

I recently assembled two computers, and everything went fine at first. One was assembled on a friday, and the other one was assembled the next monday. All week, they ran without problems. Now, after having not been used over the weekend, both had problems this morning when they were turned on.

The first one had a beep code indicating a memory problem. So after trying the memory stick in different slots, I decided to take one out of the other one (it had two running in dual channal). That got it working. So the other one now has only one 512MB stick of memory. But when I turned it on, it wouldn't work. The hard drive and cpu fan would spin up, but nothing on the screen, and no beep at all. Even though the signs didn't point to it, I decided to mess with the memory (put the one DIMM in various slots, and also putting the one from the other computer back in) and also to try clearing the cmos (unplugged the system and took the battery out for 10 mins). Neither worked.

So..what do I blame and where do I proceed? Unfortunately, both computers have different kinds of sockets for their processors, so I can't move processors around. Thanks in advance for any replies!

[Tygur]

Not that I know of, but I suppose that doesn't mean it didn't happen. Although no other computers here are showing any problems. Also, both computers were on two different surge protectors in two different rooms. I also found it strange that they both failed like that, but I don't know what to make of it.

[Tygur]

Ok, I'd like to change my question somewhat. It turns out that the problem is the power supply. I tried a different one and it worked. So now the question is how this happened.

Specifically, I suppose I'm wondering what the chances are that the two failures could somehow be related, even though it was the memory in one and the power supply in the other. The only things they have in common, though, are the surge protectors (both are on new Staples brand surge protectors bought at the same time), and the power supplies (both use the same exact model Thermaltake power supply). Actually, they do also use the same dvd burner and hard drive, but I don't think that has anything to do with the problem.

So..any opinions?