Seagate Barracuda 120 Gig Sata V - No Spin

I was going to sync my Iphone, and I plugged an Iphone USB cable into front of my 6yr old desktop that was working fine. The Cable had nothing on other end (Iphone not yet connected). The instant I plugged in the naked cable, the PC powered down totally. I unplugged the cable, and hit the restart button on front of PC. It powered back up (fans, lights on MB - even got a green NIC light, etc.), but my main Drive (this 120 gig) no longer spins, although the other (300 gig) drive does spin, No post beep from computer, no video output to screen (bios or anything), even when power and SATA cables completely disconnected from BOTH drives. OF COURSE the no-spin 120 gig drive has all my important files on it. The two little Diodes near the power connecter appear to be ok. They test about 700 in one direction, and infinity in the other using the Diode ck function on my Digital Multi-meter while the PC is completely powered down (no AC hooked to it at all) which cooresponds to the 300 gig drive that DOES spin up. Getting 12v and 5v from my power supply, and I've swapped the power connection from my 300 gig drive that does spin to the "dead" 120 gig... Still no spin on the 120 gig. Same results when I unplug my Radion AIW 9800 Pro video card from the motherboard - no spin on the 120 gig drive. It's an old computer and I have no problem with retiring everything, but I really NEED the data off the 120 gig "no-spin" drive. hope I haven't forgotten any necessary info. Oh - there was no bad head-noise, or anything. drive was sounding good until this happened. And, I have replaced the battery on the motherboard - no joy. it's a gigabyte GA-8Ik1100 MB with P4 2.8 gig CPU. Any help appreciated! Steve Henderson