Question So, I finally may have fried something; motherboard won't turn on. Passes paperclip test.

cyjackx

Honorable
Dec 23, 2013
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10,520
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I just got a new GPU and was trying to update the BIOS, so I popped the CMOS battery. I realized far too late I hadn't unplugged the power cable, and i can't even remember if I flipped the power switch (though the computer was off). When I popped the CMOS battery back in, no response to power buttons on the case or the mobo or shorting the power switch button.
I looked up the paperclip test to check the PSU, and it seems to respond with case fans et al. I know this isn't foolproof for measuring the internal voltages, but I'm going to assume it's because I touched the motherboard while it may have still been "hot" and not from PSU failure. I thought i was grounding myself; I held the case the entire time. But maybe I loosened something or bent something, because now it does nothing...
 
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I just got a new GPU and was trying to update the BIOS, so I popped the CMOS battery. I realized far too late I hadn't unplugged the power cable, and i can't even remember if I flipped the power switch (though the computer was off). When I popped the CMOS battery back in, no response to power buttons on the case or the mobo or shorting the power switch button.
I looked up the paperclip test to check the PSU, and it seems to respond with case fans et al. I know this isn't foolproof for measuring the internal voltages, but I'm going to assume it's because I touched the motherboard while it may have still been "hot" and not from PSU failure. I thought i was grounding myself; I held the case the entire time. But maybe I loosened something or bent something, because now it does nothing...
No. "Paper clip test" on PSU doesn't show true state of PSU, only that fan is working but your problem smacks more of corrupted BIOS. Start by removing battery (this time with power right off), press power button for few seconds and leave battery off for longer time (few hours to a day). Make sure you insert battery right way.
 

cyjackx

Honorable
Dec 23, 2013
10
0
10,520
1
No. "Paper clip test" on PSU doesn't show true state of PSU, only that fan is working but your problem smacks more of corrupted BIOS. Start by removing battery (this time with power right off), press power button for few seconds and leave battery off for longer time (few hours to a day). Make sure you insert battery right way.
Thank you for your incredible suggestion; removing the battery allowed boot. I then had to fiddle with built-in backup BIOSes in the UEFI before I could reboot while the battery was plugged in. The fear of god has been put into me.
 
Thank you for your incredible suggestion; removing the battery allowed boot. I then had to fiddle with built-in backup BIOSes in the UEFI before I could reboot while the battery was plugged in. The fear of god has been put into me.
Good. There are many capacitors in PSU and MB that can hold charge for some time after all power is removed and that can keep BIOS in neither state. Letting them bleed al electricity brings CMOS/BIOS back to factory default state.
 

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