Computer Powers on but no POST

Computer Set Up:
Intel - Core i5-6500 3.2GHz Quad-Core Processor
Asus - Z170-A ATX LGA1151 Motherboard
Asus - GeForce GTX 1060 3GB 3GB Dual Video Card
PSU - I don't remember the brand but it's about 500W
2x500GB HDDs
1x120GB SSD
3 Case Fans

Yesterday, while I was in a game, I heard a sound (i can't describe as I don't really remember it) and my computer shut off. I looked at it, and it was 100% shut down. I powered it back on, but it never started. All the fans lit up and came on, and the power light on the mobo was on. However, the three lights that normally light up to signify POST did not.

It was already late, but I had gone ahead and disassembled everything from the system. I pulled out the GPU, and the hdds and tried it again with no luck. I tried with the RAM sticks in different slots, with both, one and then none, and nothing changed. Then I just pulled everything with the exception of the PSU, the Motherboard and the CPU.

I changed out the PSU to a 600W PSU to see if that was the problem, but unfortunately it wasn't. The system did the exact same thing. I don't have another motherboard to test it with, nor another CPU. I live in Belize and unfortunately, these things aren't easy to come by unless I'm looking for something from possibly 2005 (if lucky). I had ordered all my parts in February and the computer has been performing flawlessly since then. I run regular tests to make sure it's functioning, and this is the first time something like this has happened.

Aside from above, I've also tried holding down the power button with the PSU plugged out, then trying to turn it on after. This resulted in the CPU light (on the mobo) blinking, but not the other 2 lights, and when I tried to replicate this, I could not.

I plugged out the power to the motherboard, and the CPU, then set it back to make sure it wasn't that. When I removed the power to the CPU, it still turned on. I removed both the power and the fan for the CPU, and everything turned on like normal except the CPU.

All that's left is for me to breadboard the machine, but that has to wait until after work -- was hoping I could have any other possibilities prior to that so I can do testing. I'm also searching for an onboard speaker locally but again, not having much luck. I figure that can help with the troubleshooting far more than brainstorming.

Thanks again for any help..

EDIT: Forgot to mention, I did reset the CMOS and that didn't solve anything. Would buying a new battery make sense just to rule it out?
Reply to Misf0rtune
7 answers Last reply
More about computer powers post
  1. Buying a new CMOS battery won't make a difference. The CMOS battery is only there to hold the settings after power off.

    Most likely something crucial went to that big bit bucket in the sky. Might be a part of the power supply, eg. 5V or 12V line, might be on the Motherboard, eg. the VRMs, might be the CPU itself...
    Reply to Karsten75
  2. You don't have a speaker attached so you can't hear POST beep codes is this correct? On page 1-30 of your manual it shows the pins to attach a speaker. Just about any little speaker will do, say from your clock/radio? Hearing those beep codes, or not, is invaluable in troubleshooting.
    When you get the speaker connected re-try booting without RAM. If you don't hear the error beep code for missing RAM then I'd bet $$$ it's a dead mobo. Especially since your PSU will power the fans. If the 'POP' had come from the PSU it's unlikely it would power anything at all.
    Have you done a visual inspection of the motherboard? Given that pop you heard it's a good idea to do that.
    Reply to Sam Poland
  3. Thanks, I think I'll do that. I did check over the motherboard, and everything seemed to look fine. It's possible I missed something, so I will check again. As for the speaker, if I take a speaker out from one of those old FM radios, how would I connect it? Do I need something additional? Just trying to get information before I get home and realize I needed something from town.. Thanks again.
    Reply to Misf0rtune
  4. You just need two wires from the speaker to the posts on the board. Just be careful where/what you touch and don't short anything. The speaker should be the smallest you can find.
    Reply to Sam Poland
  5. Okay so...

    Quick update, I couldn't get the speaker thing to work, but I did the following:
    1. Pulled the CMOS battery for about an hour,
    2. While this was out, I took my time pulling apart the PC again, and breadborded the mobo
    3. Grabbed my spare PSU, plugged it up, and it performed POST
    4. All the red lights blinked on (it stayed on RAM so I had to switch around the RAM a bit)

    -- Upon assuming that it was working, I figured the case was being affected by something, and the mobo wasn't grounded...

    Went ahead, cleaned up the case wiring, made sure everything was okay, and then started to rebuild the computer...

    -- Upon completion, I tested it again and it worked fine.... Went back into my room to put back the computer, and when I plugged it in and started it, the power came on, everything powered down for a second, then restarted and it failed once again... I figured it was the outlet, so I shifted my entire system to a different outlet.

    5. Plugged in the computer to another outlet, and it wouldn't work.
    6. Changed the voltage on the PSU, powered it on, and it came on the same.. no POST (i figured this wasn't safe to do, but I was legit just miserable)
    7. Turned the computer off, and put the voltage back to where it was. Computer performed POST and booted...

    -- I changed the outlet several times to see if it was the problem. There IS a problem with the previous outlet, but the same thing happens elsewhere. Maybe it's the wiring of this house... I'll have an electrician come in...

    8. I had to reconfigure BIOS and all that, computer restarted a few times with no problems.
    9. Windows refused to boot... After several attempts, I was starting to lose hope.. wasn't sure what the problem was anymore...
    10. Rebooted in safe mode and it almost didn't. It worked, albeit slowly and froze a lot...
    11. Rebooted in normal mode...

    Now here I am, responding from my PC -- worrying that the same thing will happen again. Mind you, the game I was playing when it cut off is on the SSD, as well as the Windows Boot folders/settings/options/whatever...

    The computer appears to be fine -- all the fans are running, the CPU is cool, the GPU is cool, and the motherboard is cool -- The BIOS had all the temps when I first booted, and am monitoring. I checked the voltage from the BIOS, and it's receiving the right voltages, but god knows if it's reporting incorrectly..

    If it happens again, I'll report back. I have no idea what to say about all of this tbh...I'm stressed and tired, and I think my heart is still at my throat. But just happy all is working atm.
    Reply to Misf0rtune
  6. Quick Update #2: ("Quick")

    Computer shut off again last night as I loaded a game. Considering the power fluctuates inside the board, I'm leaning towards PSU failure.

    Bought a new PSU (the reason I don't use the spare is because it has no PCI-e wire), and hoping that it resolves the issue.
    Last night when it cut off, I plugged in the other PSU and it booted on fine.
    I went ahead and used the original one, then it came off again.

    I stopped using it last night as i didn't want to blow any other components... If it really is the PSU, will update tonight. Otherwise, still in the air.
    Reply to Misf0rtune
  7. Thanks everyone for any assistance. Turns out it was the PSU after all. The first test on the PSU swap should have probably been done after a little time or a reset of the power. Not sure, because it was the first thing I checked with no results. Motherboard is not dead. :) Yay for small mercies.
    Reply to Misf0rtune
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