PSU Fan

Yesterday, I realized that the fan on my power supply (pretty sure it's the intake fan) is not running. I have no idea when it stopped running, and my computer has yet to meltdown.

So, my questions:

Should I be freaking out and buying a new power supply?
If the power supply does significantly overheat, what would happen?
Should I even dare to mention thinking about trying to fix it?

If you need a fan for your power supply you have big problems.

If the PSU hasn't already succumbed to heat damage, then it should only be a small job to replace the fan. If it has overheated, you should see signs of damage when you open the PSU to replace the fan (scorching on the PCB, melted insulation, bulging capacitors, etc). As long as your computer remains stable, and there are no significant signs of damage, your entire PSU shouldn't need replacing.

Sometimes things like a fan failing inside the psu signal other problems with the psu it self such as a bad product or power problems. Some fans have the connectors soldered right into the board of the psu it self.