Plug in GPU
Re-go over all the connections in the pc to be sure everything is plugged in correctly
Everything is so far. Also, it seems to turn on for a second with the message 'no signal' then go off.
Also I did some googling, if all the connections are perfectly fine and you're still having the problem, then it has a very high chance of being your PSU's fault, either by it failing, not high enough watts or from it just being a faulty PSU.
I hope not, as I don't have much money to buy a replacement.
How much money do you have because if you have like 38 bucks you can get this 500w PSU by EVGA
Roughly $30 or less, I'd have to check. Before I go and spend more money I'd like to continue troubleshooting though.
Oh, yes! That's how I fixed the last one! I do believe this could solve it (in a best case scenario that it's not actually broken). Only problem is my keyboard doesn't want to cooperate, and won't power up. Though, it might just be an issue with the fact that it's extremely old. (using the purple in/out connector with several female pins)
you sure you've got it plugged into the right PS/2 port?