New build not powering up

unclebob123 · 21 May 2023 at 16:15

I have just put together a new PC and I am encoutering a problem. I have built it out of the case to test everything.

Motherboard is gigabyte B760M DS3H
CPU is i5-13400 13th gen
Power supply isbe quiet pure power 12m

I have plugged in my 24 pin power connector to the motherboard, and the other end of that cable splits in to two cables (20 pin and 8 pin). I have plugged these I to the power supply in to the corroponding sockets labelled 'MB'.

I have also plugged in my CPU power - 8 pin on the motherboard into the P8 12v2 socket on power supply.

I have plugged in the GFX card 6+2 pins on the gfx card it's self in to the PCIe socket on the power supply.

When I turn it on I get power for perhaps 2 second, the CPU cooler fan spins up, and then it cuts out and powers down.

The fans on the GPU don't spin up at all, although they twitch a little bit when the power cuts off.

Any idea what could be wrong?

I have tried re-seating the RAM

Thanks!

13oots2 · 21 May 2023 at 19:32

I would check the socket for any bent or damaged pins, just take your time and use a good light source.

Brizzles · 21 May 2023 at 23:27

Try without gfx card, connect monitor direct to motherboard (mobo has onboard if i googled the right one.)

The 6+2 end goes into the graphics card NOT the psu ( your post wasn't 100% clear )

raralis · 22 May 2023 at 00:21

Try reseating the cpu + heatsink and try powering up without the graphics card as Brizzles suggested.

Might not be relevant, check the kettle cable is plugged in the PSU properly. Seen a few PCs power up for a second or 2 at most, only to find the kettle cable wasn't fully plugged in.

lsg1r · 22 May 2023 at 01:13

Any lights/codes on the motherboard?

First thought for me was thermal throttling but seems a little too quick so like others I'd be checking the cpu side of things.
You don't mention it but I assume there is a boot drive of some sort installed, some motherboards just won't boot without one installed.

Other than that it's really a systematic check of things.... is everything seated correctly, are all the cables correctly plugged in etc.