Long story short, I bought a used ECS nForce3-A motherboard (for Socket 754) to replace a less-than-ideal board that I had previously been using. After I discovered that the new board was dead (no power to the CPU whatsoever), I obviously tried swapping back in my previous one. Strangely, however, when I replaced it, I couldn't get any power going whatsoever.
Upon wiring everything up and flipping the switch on the power supply, I can either hit the power button on my case or manually short the power switch on the motherboard, but either way, nothing turns on. I've tried reseating everything; RAM, CPU, one stick of RAM in this slot, etc. I've also tried clearing the CMOS, but to no avail. I doubt the board accidentally shorted out, because it gives the same symptoms regardless of whether it's mounted inside the case or out, and I've mounted the board several times in several different cases without any issues. No matter what I do, I get neither power nor any beep codes. I'm absolutely stumped.
The only thing I can think of that may
have caused this is that, in my attempts to get the newer board to work, I tried swapping out its CMOS battery for the one in the old board (they so happen to use identical batteries).
The motherboard I've been using is an Asus K8S-LA, an OEM motherboard apparently used by Compaq. All of the components in use (nForce3-A excluded) were working perfectly before I attempted to switch the boards out.
Relevant specs as follows:
Thermaltake TR2 430W
Athlon 64 3400+ (NewCastle, for those who are wondering)
2x512MB DDR400 (one stick Crucial, another of Corsair)
I've never been this baffled before, and I've wasted a lot of Artic Silver in the past few days. Help, anyone?
Please just tell me it's something simple, like, "your PSU's shot." At least that's still under warranty.