First of all, what was your previous and current power supply model numbers?
Second, go to the control panel power options and turn off/disable the "fast restart" option. This hybrid sleep setting has been wreaking havoc on many systems.
Third, make sure you have the very latest bios version for your motherboard installed. Might even be a good idea to reset the bios to default settings by removing the cmos battery for five minutes, then putting it back and rebooting.