Last night I had my Emachines T6412 PC plugged in to my APC battery backup. (It is stock except there is an extra hard drive installed, and also two random video cards I found in scrap computers, and a wireless card I also found in a scrap computer.) Earlier the red light on the backup indicating that the battery needed replacing was blinking red, but I figured no big deal, cuz I rarely need the backup anyways. Anyways I had the backup turned off, the computer was plugged into the side that supports backup and surge protection, and I had 2 monitors plugged in as well via VGA thru the 2 random video cards I found. I then powered on the battery backup, and three seconds later there were two loud pops in the back of my Emachines. After turning off the backup, I checked it out, but there didn't seem to be any trouble structurally. So because of a school policy, I had to wait until morning to turn on my computer, and when I tried, there was no response from the computer at all. (I had already turned the backup back on, and this time the red "replace battery" light is not flashing. Also no loud pops either.) So I am assuming that the thing is fryed? If so, Is it just certain parts? Also, is there any way to fix it at all? Also is my hard drive data gone? (My hard drive is a HDD) Also, I'm not sure if this affects anything, but the secondary hard drive, the one without the OS, was accidentally unplugged while the computer was turned on, and the computer momentarily crashed. It turned back on fine once I reattached the connection. I have a random AMD mobo I salvaged, and some AMD processors that might work if I'm lucky. Would that even be possible to replace the current mobo and CPU with those parts?