[SOLVED] New pc not going through POST screen, can't turn it off with power button.

[Padisky]

Hi, I have a newly built pc and when i turn it on, every fan and light turns on, but the pc is not going through POST screen, so its not booting up, but every time i fiddle inside the computer case (switching rams, putting in / removing system speaker etc..) it boots up every once in a while. When it successfully boots up, everything runs fine, i can even restart the pc and it works fine, but when i turn it off and go to sleep the next morning it does the same thing, no POST. The weirdest thing is that when the pc turns on and does not go through POST, i cannot turn it off, no matter how long i press the power button, the only way i can turn it off is by switching off the PSU. When the pc is not going through POST the pc speaker makes no sound, when the pc boots up the speaker makes one beep, implying that everything is fine. Another information that might be useful if the pc boots up, and the boot priority is set to the SSD, it says reboot and select a proper boot device. If the boot priority is set to windows boot manager, the pc boots up and the ssd works fine.

SPECS:

NZXT Midi H510 Case

Chieftec photon 750W PSU

AMD Ryzen 7 3800X CPU

Gigabyte x570 GAMING X Motherboard

2x8GB 3600mhz DDR4 Kingston HyperX Fury Black Series CL17 (HX436C17FB3K2/16) RAM

Gigabyte GeForce RTX 2070S 8GB Gaming OC 3x GPU

Kingston 960GB SA400S37 SSD, and 2 of my older HDD's.

Windows 10 pro

Things i tried:

Switching RAM positions/trying other rams.

PC speaker

Pulling out / switching peripherals.

Overclocking the RAMS(XMP)

Tested the PSU with a power supply tester, everything is fine.

Reinstalled windows

Updated BIOS and all drivers

Checked if the motherboard is successfully installed and is not short circuiting, it seems fine.

I really feel like I'm out of troubleshooting options here, any help would be appreciated.

 

[geofelt]

I suspect you have a poor quality or defective psu.
My recollection is that chieftec is not a good brand.
See if you can't test with a known good quality psu.
Psu testers are worthless. They can confirm a dead psu, but can not test for proper operation.

 

[Padisky]

I suspect you have a poor quality or defective psu.
My recollection is that chieftec is not a good brand.
See if you can't test with a known good quality psu.
Psu testers are worthless. They can confirm a dead psu, but can not test for proper operation.

I've tried it with another PSU from a working computer and it did the same thing, so its not the PSU.

 

[gamenadez]

Its the Mobo defective. try to buy a cheap mobo and test it..