some pins on my fan on my desktop got bent as I tried to re-seat it, and now it won't power up. will straightening the pins be enough, or so I need to get a new fan
What.
Fans don't have pins. Maybe you should elaborate.
If you are referring to your processor, so long as none of the pins are broken, and you can carefully bend them back into position, you'll likely be ok. I've rescued hundreds of CPUs this way.