Power Supply Woes

[SalmonMan]

I just received a new power supply today after previously thinking that my old one had gone down. I diagnosed the problem by using speedfan and found out that the 3.3v connector was only outputting 1.54v's. However, once I removed the motherboard connector on the old PSU, I saw that 4 of the connector pins were burnt and somewhat melted (the plastic part around them, that is), all belonging to the red wires from the connector. I simply ignored it thinking that it didnt matter because the power supply was bad anyway, but once I installed the new one and ran speedfan again, it had said that only 1.54 volts were still being output, yet the system ran fine.

Some other sources then told me that the mothreboard may be trying to draw too much power, and that it should be replaced. I thought that it would then be hot because the old one was somewhat melted, but after playing Half Life 2 for several hours and then shutting down the computer and then immediately removing the motherboard power connector, the connector was not hot at all. Can anyone tell me what is wrong, and what to do about it? Since replacing the old power supply, the computer has been completely stable, but I dont want the new PSU to go bad too just because of the motherboard.

The new one is a thermaltake 480W, while the old one is a turbolink 420W that came with my chieftech case.