Is my Power Supply able to be fixed?

[Tomarama24]

A few months ago my PC started restarting several times when powered on and would take up to 20 minutes sometimes to get to the desktop screen where it would usually not restart again until powered on again. (Sometimes it would restart after but not often). The error logs would say there was an unexpected shutdown.

I sent the original PC I had off to repair as it was free and they replaced several parts and said it was fixed. One month after getting it back it didn't have a problem so I deiced to put in the only two other parts I had in the PC back in.

A 500w power supply and a Raedeon 2GB 5450 as I wanted to use the HDMI port again for my TV.
The problem started up again as it was. I removed the graphics card first tested it for a few days and the problem persisted, for about a month now I've swapped back down to the smaller original power supply and no problems.

It seems fairly obvious the 500w power supply is the problem but it would still work so I would like the know if there was a problem that I could fix myself or have fixed for cheap by a professional.

Thanks.

 

[b0w]

I don't see how the PSU would be the problem. Maybe the CPU Rail is malfunctional and your CPU throttles down itself... Anyway, when you don't have problems with the smaller PSU, just use it then.
Which PSU models are both exactly?
The only thing you could fix yourself on a PSU is to replace the fan, but I guess the fan works, otherwise the PSU would shut down. Also you could watch for disconnected cables inside, but any more, such like replacing condensators, would be dangerous, especially afterwards. Even the two things I mentioned require precautions made, so don't do anything yet. First write down the model, so we can see if it's worth it at all.

 

[Tomarama24]

I don't see how the PSU would be the problem. Maybe the CPU Rail is malfunctional and your CPU throttles down itself... Anyway, when you don't have problems with the smaller PSU, just use it then.
Which PSU models are both exactly?
The only thing you could fix yourself on a PSU is to replace the fan, but I guess the fan works, otherwise the PSU would shut down. Also you could watch for disconnected cables inside, but any more, such like replacing condensators, would be dangerous, especially afterwards. Even the two things I mentioned require precautions made, so don't do anything yet. First write down the model, so we can see if it's worth it at all.

Thanks for the reply.
I've since bought a new power supply, the PSU I had was too small wattage to support my graphics card and it's model is (hp-d250aa0) the higher wattage one which isn't working model is (ATX-500 (Intel ATX 12v 2.3 (PPFX)) 500w)

The PSU would load and work fine but would cause PC. My new PSU works fine with everything so I figure it has to be something to do with the old PSU.

Sorry for late response forgot about post.