|Suspect the power supply first, but the damage could be more extensive. If you have a power supply you can substitute (borrow), then try that. If you can boot into the BIOS set up then you can read the voltages which need to be within 10% of specs, if not then a digital volt meter can give you the outputs. Establish that the power supply is working before purchasing anything else. If you can purchase a power supply with the understanding that you can return it for a full refund if it does not help or the damage is too extensive to repair, then that may be worth trying.|
You have to be a little bit crazy to keep you from going insane.