Broken Mobo, PSU or CPU?

[eggfriedbryce]

My current setup is:

i7 6700k

16GB RAM

Asus Z170 Pro motherboard

RTX 2060 (installed about 1 week ago)

Corsair HX850i PSU (way more power than I need, I know)

 

I turned off my PC around 2pm yesterday, went back to it three hours later, pressed the power button and got nothing. Thought it might be the button to blame but jumping the pins on the mobo didn't do anything either. No signs of life except the pwr LED on the motherboard is on (my mouse and kb rgb is also lit up). No fans start. The test fan button on the PSU does work and the PSU fan spins when it is pressed. I have tried removing the GPU, RAM and CMOS battery to no avail. I built the PC back in summer 2016 and it has worked flawlessly up until now, including for the last week with the RTX 2060 I just installed. I am trying to ascertain whether I have a Mobo, PSU or CPU issue on my hands. Obviously all PC stores are closed at the moment and I need my computer for studies and work (and gaming, else I'll be fantastically bored during this lockdown), but don't want to waste my time buying a new motherboard if the CPU is at fault or vice versa. Any help would be much appreciated, thanks in advance!

[wall03]

13 minutes ago, eggfriedbryce said:

I have tried removing the GPU, RAM and CMOS battery to no avail. I

Did you replace them with components that you know work? Or did you just take them out? I don't think it is the PSU

[RenaKry]

A motherboard can power on without a CPU, but since pressing the power button does not turn on the power supply, there is either a problem with the power supply or the motherboard. If the power supply turns on if you jump the green wire pin 16 on the 24 pin connector to ground using a paper clip, then the power supply is not the problem. You should refer to this pinout, since your power supply cables are all black.

Power supplies have safety features that prevent fires, so they can seemingly "fail" for any reason, but I wager the most common reason why a power supply doesn't turn on is because of a short circuit.

If you can turn on the PSU by jumping it, then the motherboard is likely the culprit.

[eggfriedbryce]

7 minutes ago, wall03 said:

Did you replace them with components that you know work? Or did you just take them out? I don't think it is the PSU

I have integrated graphics on my CPU so I just took the GPU out. I don't have spare RAM modules but tried with one each at a time. 

[eggfriedbryce]

6 minutes ago, nelsonpong said:

A motherboard can power on without a CPU, but since pressing the power button does not turn on the power supply, there is either a problem with the power supply or the motherboard. If the power supply turns on if you jump the green wire pin 16 on the 24 pin connector to ground using a paper clip, then the power supply is not the problem. You should refer to this pinout, since your power supply cables are all black.

Power supplies have safety features that prevent fires, so they can seemingly "fail" for any reason, but I wager the most common reason why a power supply doesn't turn on is because of a short circuit.

If you can turn on the PSU by jumping it, then the motherboard is likely the culprit.

Thing is my PSU fan doesn't even turn on until a load of like 300W so how would I know it had started?

[fordy_rounds]

1 hour ago, eggfriedbryce said:

Thing is my PSU fan doesn't even turn on until a load of like 300W so how would I know it had started?

You could plug an HDD (not SSD) into a sata power cable. They'll spin up even without a data cable. So if the HDD spins up (it's audible) then your PSU has turned on.

Alternatively, if you have a multimeter, use that to check voltages. If you get proper readings (i.e. 12V between a 12V pin and a ground pin) then you're powered up.

Edited May 5, 2020 by fordy_rounds
Added multimeter test suggestion.

[eggfriedbryce]

36 minutes ago, fordy_rounds said:

You could plug an HDD (not SSD) into a sata power cable. They'll spin up even without a data cable. So if the HDD spins up (it's audible) then your PSU has turned on.

Alternatively, if you have a multimeter, use that to check voltages. If you get proper readings (i.e. 12V between a 12V pin and a ground pin) then you're powered up.

I thought about that, unfortunately lockdown has me stuck away from home and I don't have a hard drive I don't care enough about to test that theory on (at home I have two old rigs I could test all these components in, it's really frustrating). I've just been doing more troubleshooting and realised that my PSU is making a clicking sound when the power button is pressed (or the mobo jumped), it makes me suspect the PSU has failed.