Looking at your hardware specs I would think the mobo died before the power supply.
If your mobo is using a Award Bios then 63 is Initialize Mouse - Detect if mouse is present, initialize mouse, install interrupt vectors
If your cpu overheated a little in the overclocking session and the thermal paste was old it might have contaminated the thermal interface causing it to overheat and lockup after a few seconds (under a minute).
Try removing the heatsink and cleaning it and the top of the cpu with rubbing alcohol and then applying new paste. If you don't have any paste buy some and wait until you have it before proceeding. While your at it clean the heatsink fins and fan with compressed air. After reassembling everything don't forget to plug the fan into the mobo power header. It might work and it might not, here's a link to some cheap but good thermal paste.
Newegg.com - Tuniq TX-2 Cooling Thermal Compound - Thermal Compound / Grease