Question Old PC won't boot after PSU and HSF change

Mar 30, 2019
3
0
10
I recently upgraded my PC and gave my old build to my little brother (minus PSU and HSF). I wasn't able to be there to set it up since we didn't know we'd need a new HSF and I had to head back home.

Anyway, he replaced installed the HSF and PSU with some problems (at one point he had the GPU and CPU power flipped, whoops), but overall everything should be set up correctly now. The issue is that the PC will power on but nothing displays on the monitor. He's also telling me that the keyboard is not turning on, but that it definitely had been the first couple of times he tried to turn the PC on. Sometimes the PC will be turned on, then rapidly turn off and on again, apparently randomly.

So far I've told him to try no GPU, CMOS battery reset, every RAM slot individually. The PSU is confirmed to work with a previous system, that's the only new hardware other than the HSF.

This computer had been behaving oddly for me towards the end as well. I'd tried upgrading the RAM and came across the same on - off - on pattern, but it would start up in the end. One thought I had was the motherboard has just given out, though I'm not sure why it would, it's only like 3 years old.
I'm not sure what the next step is, maybe removing mobo from the case and trying a breadboard setup.

Please let me know what you guys think!

The specs are:
i5 6600k
1070
CX750
1x 8GB RAM
ASUS Z170E
 
Mar 14, 2019
58
7
45
I recently upgraded my PC and gave my old build to my little brother (minus PSU and HSF). I wasn't able to be there to set it up since we didn't know we'd need a new HSF and I had to head back home.

Anyway, he replaced installed the HSF and PSU with some problems (at one point he had the GPU and CPU power flipped, whoops), but overall everything should be set up correctly now. The issue is that the PC will power on but nothing displays on the monitor. He's also telling me that the keyboard is not turning on, but that it definitely had been the first couple of times he tried to turn the PC on. Sometimes the PC will be turned on, then rapidly turn off and on again, apparently randomly.

So far I've told him to try no GPU, CMOS battery reset, every RAM slot individually. The PSU is confirmed to work with a previous system, that's the only new hardware other than the HSF.

This computer had been behaving oddly for me towards the end as well. I'd tried upgrading the RAM and came across the same on - off - on pattern, but it would start up in the end. One thought I had was the motherboard has just given out, though I'm not sure why it would, it's only like 3 years old.
I'm not sure what the next step is, maybe removing mobo from the case and trying a breadboard setup.

Please let me know what you guys think!

The specs are:
i5 6600k
1070
CX750
1x 8GB RAM
ASUS Z170E
How much watts is your current psu?
 
Mar 30, 2019
3
0
10
S

Hmm could be the old mobo then. Maybe try switching your old psu’s back to see if it works, if not then it has to be your mobo.
I would try that, but I don't live there. Can't do anything in person for the immediate future. It would be odd if it was the PSU since it is a higher wattage than mine and worked in a previous PC