Question PC turning on and straight back off, repetitively.


Mar 14, 2015
So I hadn't used my PC in a while but before that it was in good working order. Now when I try turning it on, it starts to boot up for about a second then switches back off. Without pressing the on button it will do this repetitively until I cut the power. The specs for my system are as follows:
CPU: Intel i5-4690K
MB: ASRock Z97
GPU: GeForce GTX1070ti
PSU: EVGA 650 G2
Case: Zalman Z9
RAM: 2xHyperX blu 4gb
Storage: 1xcrucial 128gb SSD 1xSeagate 500gb HHD

Reading up on this it seems it may be the PSU, is there a way to test my PSU without a spare? I will be reassembling the PC to make sure it isn't because of any lose cabling but any other thoughts on what it may be/what to do are greatly appreciated!


I'd pull the graphics card and memory out, and then reinstall them, to make sure the connections are good.

Make sure that when you power on, the CPU cooler fan is spinning, because if it's not, most systems will shut right back off.

Then, if nothing else, try resetting the BIOS with a hard reset.

Power off the unit, switch the PSU off and unplug the PSU cord from either the wall or the power supply.

Remove the motherboard CMOS battery for five minutes. In some cases it may be necessary to remove the graphics card to access the CMOS battery.

During that five minutes, press the power button on the case for 30 seconds. After the five minutes is up, reinstall the CMOS battery making sure to insert it with the correct side up just as it came out.

If you had to remove the graphics card you can now reinstall it, but remember to reconnect your power cables if there were any attached to it as well as your display cable.

Now, plug the power supply cable back in, switch the PSU back on and power up the system. It should display the POST screen and the options to enter CMOS/BIOS setup. Enter the bios setup program and reconfigure the boot settings for either the Windows boot manager or for legacy systems, the drive your OS is installed on if necessary.

Save settings and exit. If the system will POST and boot then you can move forward from there including going back into the bios and configuring any other custom settings you may need to configure such as Memory XMP profile settings, custom fan profile settings or other specific settings you may have previously had configured that were wiped out by resetting the CMOS.

In some cases it may be necessary when you go into the BIOS after a reset, to load the Optimal default or Default values and then save settings, to actually get the hardware tables to reset in the boot manager.

If that still doesn't help, disconnect the storage devices, and see if that works. Maybe a faulty drive is triggering the restarts. Short of any of that working, you might need to end up benching the board to find the problem.

Take a look at the board to make sure there are no signs of faulty capacitors such as bulging, leaking or similar signs of problems. Make sure nothing is stopping any of the fans from spinning and that everything is plugged in correctly. Unplug and reconnect the ATX 24 pin and EPS 4/8 pin connectors as well.