My pc nearly died. First the power supply fuse for the plugs in my house "Blew"(Its a modern one so a switch is just flipped. Note i mean the actual house's power rather than the pc.). When the switch was flipped back and i tryed to turn the pc on, it just turned its self off after 4-5 seconds.
I and my Dad (Who both know practicaly nothing about hardware, except what each thing is (Memory, CPU, GFX Card, etc)) tryed taking out nearly everything to see if it would help(Excluding the Ram and CPU). I at this point had given up all hope. My dad however removed the Battery that was attached to the Motherboard. The computer then loaded and would go into BIOS(Tho wouldn't remember any settings as it had no battery).
Once the hard drive was placed back in (And a battery put in to replace the old one) the computer would then not detect the Hard drive. We tryed removing the power + "whatever the gray cable is called" cables and puting them back in, trying the slave ones instead of master, etc. Nothing worked. I found a "whatever the gray cable is called" in my hard drives box (Bought a replacement one last year) and replaced the old gray cable. And the pc lived

.
Yay!