Turns on then after a few seconds back off

[Kiryu611]

So I recently swapped motherboards out, the one I put in wasn't working [computer guy told me it was broken but I thought maybe he just did the swapout with a cheap Mobo to rip me off. This was before I knew about computer parts]. I put it in, it was broken after all. Figured hey, no sense being bugged about it.
Put my other one back in, plugged it all in, forgot the front connectors and thought "Oh noh, it wont work when I press power" but fixed that issue and was relieved.
Then I turned it back on and the fans and leds all turn on and then a few seconds after back off.
No post, no beeps, nothing. I reseated every single thing in the computer, even switched it out with all my old fully working parts. Even my PSU in case it was a power issue, but nothing worked.

So is this a cpu or motherboard problem? I want to know what's broken because I was going to buy new parts anyway since I was working on my dream build but I didn't want to buy the mobo and it be the cpu since some games are coming out an I wanted to play them.

Any ideas? 🙁

Specs:760GM P23FX Mobo
amd 4300 [was swapping, reason I needed to switch mobos]
sapphire dual x 280x
8GB X1 ripjaws
500w evga PSU

Any sort of help at this point is greatly appreciated!

 

[Onus]

Reset your CMOS to defaults using the jumper on the motherboard.

 

[Kiryu611]

Reset your CMOS to defaults using the jumper on the motherboard.

Reset the cmos and it still does it. I even tried resetting it before, which I forgot to mention, but figured I'd try again. Before my issue was no display, but now it's no display and turning off after like 5-30 seconds, usually around the same time but you get the idea. 🙁

 

[Onus]

Try putting the RAM in a different slot. Do you have a case speaker (or piezo on the mobo), and are there any error beeps?

 

[Kiryu611]

Try putting the RAM in a different slot. Do you have a case speaker (or piezo on the mobo), and are there any error beeps?

Put my normal ram in another slot, nothing, switched with my old ram and did the same in both slots, nothing. I've tried just about everything now. If it's broken it sucks but I'd rather know which one specifically is broken so I can switch it out instead of buying one and it turns out the other is broken :\

 

[Kiryu611]

Try putting the RAM in a different slot. Do you have a case speaker (or piezo on the mobo), and are there any error beeps?

I just tested it again, turned it on, it turned itself off, tried with a different video cable, still nothing, though I noticed when I went to reseat the CPU it was VERY very hot. It was on for a max total of a minute inbetween the two boots I tried

 

[Onus]

Make sure the cooler is properly mounted. If you had to remove it, clean off the existing thermal paste and apply a fresh layer.

 

[Kiryu611]

Make sure the cooler is properly mounted. If you had to remove it, clean off the existing thermal paste and apply a fresh layer.

Cooler mounted, plugged in, computer now no longer shuts off but there's still no display! Dead mobo? I mean if it is it's sorta bad news but it's better than cpu or both being dead. I had it run for a while just to make sure and still no

 

[Onus]

Remove your graphics card and try mobo video and see if that works. If it does, get into your BIOS and set it to make the PCI (or PEG) adapter is set as Primary. Then re-install the graphics card, connect your monitor to that, and see if it works again.

 

[Kiryu611]

Remove your graphics card and try mobo video and see if that works. If it does, get into your BIOS and set it to make the PCI (or PEG) adapter is set as Primary. Then re-install the graphics card, connect your monitor to that, and see if it works again.

An issue I've had with my mobo is when the computer even worked I couldn't get the mobo graphics to work, though I suppose at this point I'll try anything

 

[Kiryu611]

Remove your graphics card and try mobo video and see if that works. If it does, get into your BIOS and set it to make the PCI (or PEG) adapter is set as Primary. Then re-install the graphics card, connect your monitor to that, and see if it works again.

Nope, no change 🙁 I mean I've swapped everything but processor and mobo before and it had the same results, so I think it's just my mobo is dead. It starting then turning off was probably the fan on my cpu but this issue seems to be the mobo. Had the same issue with my old dead mobo so I guess investing in my new one will fix this? I mean, I was going to this month anyway but it breaking sucks a whole lot. I probably shocked it like a twat, so I invested in a static wrist band along with it. 🙁 Unless you think its something else, something fixable?