Question Please help with PC not POST-ing

monardo

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Jan 31, 2014
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The background:

Someone at my home disconnected UPS, which got completely discharged and as a result my desktop PC turned off. When I came back and tried to switch on the PC, there was absolutely no reaction on Power button press. I took it apart, and first I checked PSU, which would not start when I shorted 15 and 16 pins. So I went and bought new PSU. I removed graphics card, connected monitor to integrated HDMI, hooked-up CPU and MoBo cables to new PSU and pressed the power. The CPU fan started to turn, but there was no POST (absolutely no signal going to monitor). After trying lot's of stuff (swapping RAM sticks, resetting CMOS, trying various cables and monitors), I decided that motherboard is fried and bought new one.

So here is what I have now as a barebone:
new MB, new PSU, 1 stick of RAM (which probably works as I have 4 different sticks and they can't be all faulty) and Old CPU (with cooler). I removed all hard drives. When I press power, the MB light's up, CPU fan starts to turn, but there is still no POST or any signal going.

So,

1. Is it busted CPU?
2. Is there a way to test before I go and buy new CPU
3. Could there be anything else that I missed or a test which would pinpoint the problem.
4. Could faulty PSU burn CPU (and maybe MB, as I am not sure anymore that old one does not work)

Please help

P.S. The system spec of barebone components:
MB - Asrock B560M Pro4 LGA1200
CPU - i7-10700F
PSU - ZALMAN TeraMax [850W]
RAM - G.SKILL Ripjaws V 32MB
 
Last edited:

sitehostplus

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Jan 6, 2018
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What the other poster said about system specs, and also list any other symptoms. Pay attention to motherboard lights and codes, and do you hear any beeps.

Also, have you tried plugging it in without the UPS? Sometimes when you drain a battery that low, it kills the battery, and there is no bringing it back.

As far as the CPU is concerned, best way to test is in another machine. Just take the CPU itself down to a local computer shop and pay them to test it. If they can get it working, it's good. If they can't, you know what to do next.

Good luck, happy bug hunting, and may the odds always be in your favor! (been watching Hunger Games)
 

monardo

Distinguished
Jan 31, 2014
11
0
18,510
What the other poster said about system specs, and also list any other symptoms. Pay attention to motherboard lights and codes, and do you hear any beeps.

Also, have you tried plugging it in without the UPS? Sometimes when you drain a battery that low, it kills the battery, and there is no bringing it back.

As far as the CPU is concerned, best way to test is in another machine. Just take the CPU itself down to a local computer shop and pay them to test it. If they can get it working, it's good. If they can't, you know what to do next.

Good luck, happy bug hunting, and may the odds always be in your favor! (been watching Hunger Games)
I only test without UPS.
Motherboard has no beeps, but I think it has no built-in speaker and it's brand new (just bought today). Since exactly same happens with old MB, I doubt both are faulty - what are the odds :)
 

sitehostplus

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Jan 6, 2018
400
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I only test without UPS.
Motherboard has no beeps, but I think it has no built-in speaker and it's brand new (just bought today). Since exactly same happens with old MB, I doubt both are faulty - what are the odds :)
Very true, but a lot of motherboards have troubleshooting stuff built into them that can narrow down your problem. Beep codes also help.