No power after startup problems

[Sync_]

Hey, this morning my PC gets no power after weeks of having problems on startup. The last few weeks the fans would turn on for a short amount of time and then turn off and on again while holding the power button.

I attached a video of the described behaviour. Since this morning I get no power at all.

 

Things I already tried:

-change the CMOS battery

-jump the power supply (did work, fans did spin and light up)

-jump the power switch pins (did not work)

-measured the power switch pins (power switch does work)

-checked the mainboard for visual damage (none found)

So now that I have ruled out the PSU or power switch I am kind of lost how to check my mainboard. What can I do the further check the system and identify the issue?

 

Specs:

ASRock B550 Phantom Gaming 4/ac Ryzen 5 3600XT

RTX 3070 FE

Gigabyte P750GM as PSU

 

 

[Supersonicwolfe]

53 minutes ago, Sync_ said:

Hey, this morning my PC gets no power after weeks of having problems on startup. The last few weeks the fans would turn on for a short amount of time and then turn off and on again while holding the power button.

I attached a video of the described behaviour. Since this morning I get no power at all.

 

Things I already tried:

-change the CMOS battery

-jump the power supply (did work, fans did spin and light up)

-jump the power switch pins (did not work)

-measured the power switch pins (power switch does work)

-checked the mainboard for visual damage (none found)

So now that I have ruled out the PSU or power switch I am kind of lost how to check my mainboard. What can I do the further check the system and identify the issue?

 

Specs:

ASRock B550 Phantom Gaming 4/ac Ryzen 5 3600XT

RTX 3070 FE

Gigabyte P750GM as PSU

 

 

I assume you already tried the "no post guide" on the forum?

 

If not, try that. or start with minimum system: Only CPU, one stick of ram, GPU. No extra fans (just the AIO pump), no storge, no USB/audio header plugged in

[Sync_]

20 hours ago, Supersonicwolfe said:

I assume you already tried the "no post guide" on the forum?

 

If not, try that. or start with minimum system: Only CPU, one stick of ram, GPU. No extra fans (just the AIO pump), no storge, no USB/audio header plugged in

Yes, I tried all the steps and it still won't start as a minimum system. Is there any option to check if my motherboard is dead other than checking the PSU and powerswitch?

[Supersonicwolfe]

4 hours ago, Sync_ said:

Yes, I tried all the steps and it still won't start as a minimum system. Is there any option to check if my motherboard is dead other than checking the PSU and powerswitch?

Not without trying a known good board or try the components on a known running computer.

 

Also that PSU did have a voluntary recall, I hope yours isn't in the recall range. I would try a new PSU first. 

 

[Sync_]

On 7/16/2023 at 4:54 PM, Supersonicwolfe said:

Not without trying a known good board or try the components on a known running computer.

 

Also that PSU did have a voluntary recall, I hope yours isn't in the recall range. I would try a new PSU first. 

 

Hi, sorry for the delayed answer. Shortly after my post, everything started working again for half a week. Then I went back to having no power.

 

I got a new PSU (Cooler Master MWE 750 V2) and got my mainboard out of the case for better testing. I am now running in a weird issue:

 

When I connect the new PSU with the mainboard (only CPU, 1 stick of RAM and GPU) and bridge the power button pins i hear a click in the PSU and the POST-LEDs for CPU and DRAM blink for half a second. Nothing happens after. This only works once and can only be repeated after completely removing the power cable from the PSU and waiting for a bit.

 

When I use the cables of the new PSU with the old PSU the CPU and DRAM-LEDs blink when the mainboard is connected to power even before I bridge the power button pins. When I bridge the pins nothing happens. The CPU does not get hot. What could be the issue here?