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Question My PC is turning off and on repeatedly. Tried many solutions.

Jul 7, 2020
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Hi all,

Woke up this morning and my PC would not properly turn on. When I press the power-on button it lights up (so does the gpu and motherboard) for around 0.5 - 1 second then turns back off again. It keeps trying to turn itself on again every 4ish seconds after that and failing after 0.5 - 1s again. I cannot get to the bios screen or anything as 0.5s is too short.


Things I have tried so far:

- Disconnected GPU and tried running without that in (using onboard)

- Tested each individual RAM stick in slot 1, and different slot. Reseated RAM.

- Dusted and tried to find any loose connections

- Looked for any burn marks on motherboard (some parts of the back of motherboard haven't been unchecked as didn't want to remove whole thing)

- Reset CMOS battery (putting on pins 2&3 for 15 seconds, and also removing battery for 30 seconds)

- Disconnected all USB and other physical inputs. Only power cable remains.

- Unplugged power button on case in case it was shorting

- Unplugged all SSDs and HDDs

- Reinstalled CPU cooler, including cleaning and applying new thermal paste

- Tested PSU with paperclip

- Removed all components except PSU, Motherboard (24 pin and 8 pin CPU connector only), 1 RAM, CPU (and Cooler).


Symptoms:

- PC would turn on for ~0.5s then off again. Keeps trying to boot.

  • Once CMOS battery was removed and reinserted, it lasts on for about 5 - 15 seconds. It once lasted 1minute without the GPU in after removing and reinserting the battery. This makes me believe it might be something to do with this CMOS battery component, as this is the only tampering that has yielded somewhat positive results? But I thought the CMOS battery only kept track of date/time etc. However I'm unsure and unexperienced.
  • When it hasn't been turned on for a while, it lasts a few more seconds the first time I try to start it. Then back to it's usual 0.5s boot loop. It doesn't make it to BIOS.
Specs (if helpful):

GPU - 2070 Super

CPU - i5 4690k

CPU Cooler - Cooler Master 212

RAM - 4 x 4 ddr3

Motherboard - Asus Z97A

PSU - 650W FSP AURUM S Gold

3 SSD and 1 HDD


Apologies if this is the wrong place to post this, feel free to move or let me know if so.


Any advice or wisdom is welcomed,

THANKS!
 
Last edited:

Phillip Corcoran

Titan
Moderator
The paper-clip test only proves that your PSU isn't dead, it doesn't prove that it's okay under load (ie when it has to actually provide sufficient power to the entire system). So it's still suspect, especially in view of the symptoms you mentioned.
 

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