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PC won't turn on, fans & LED's start for a second then stop

Dec 15, 2018 8:34PM PST

The previous day to this post an electrician came over to install ceiling fans and in doing so he turned the power off so without me knowing I tried to turn my pc on and it did what it is doing now, the fans run and leds for about half a second then die.

The thing is I had the problem yesterday and fixed it by replugging the PSU and mobo cables then replugging the hard drive cables and it worked at that. However I now have the same problem this morning and I've tried what worked previously and nothing just the same power boot as described. The only thing that has changed since yesterday is I turned the power off at the wall like every other night.

Ive tried different ports at the wall and I've concluded the power board is fine, I'm just confused because I fixed it yesterday and now it's acting up again, any help would be greatly appreciated!
Thanks, Patrick.

What I've tried as of today:

- booting without USB accessories, GPU, 1 Ram stick, system fans or hard drives.
- replugging PSU cables and mobo cables
- Taking out mobo battery
- cleaning ram sticks
- dust cleaning everything


CPU: I5 6600k
GPU: MSI GeForce Gtx 1060 6Gt Oc
Mobo: Asrock Z170 Pro4/D3
Ram: Kingston Hyperx fury 16gb DDR3 (2 x8gb)
CPU cooler: Hyper 212 Evo
PSU: EVGA supernova 750w

Discussion is locked

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Make it smaller
Dec 17, 2018 11:15AM PST

Start unplugging stuff until you get down to
Psu + mobo + cpu/hsf.

If it still won't power up your down to 3 parts.

Before you change any of those replace the cmos battery.

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Solution to "PC won't turn on, fans & LED's start for a sec"
Dec 17, 2018 11:17AM PST

I have faced similar issue few days earlier. Apart form what you have already tried, make sure you check the following:
1. Check if the cooler is working properly. All the pins must be locked properly. Although the fan starts, there may be some issue with the cooler setup that can cause overheating & the system to shut down.
2. If cooling paste is used with your cooler, you need to clean & reapply the cooling paste. Use an optimum amount of cooling paste. Excess amount can insulate the system.
3. In the boot menu, check if the primary boot device (HDD or SSD) is currently installed in your system. If your primary boot device is not integrated, there may be a boot error. But, in order to check the boot menu, you need to run your PC first. Therefore, reconnect every cable from the beginning and then check this step.