Motherboard issue

[Chiyawa]

Hi,

 

I have a PC with MSI motherboard: H81M-P32L. The issue right now is when the system start, it seems to switch the PSU off then on then off then on again. I tried with different known good PSU but it still behave the same.

 

Does anyone face this similar issue? I tried quite many things and still stuck over here.

 

So, what I have tried:

- Change PSU. It works for a few days before it happens again. The said PSU works perfectly in other system (and currently still is in another system). PSU is generic Pentium 4 era with 4-pin 12V CPU and 20-pin ATX Power with total power of 400W where 12V is 238W max. The system works for quite a while before having this issue again

- Change to a new modern PSU with higher capacity of 450W (Silverstone brand, 12V output max is 448W), and it works for a day, then the system failed again

- Test with all peripherals (HDD, SSD, CD-ROM) detached, same result.

- Test only the motherboard with CPU only (removing RAM, GPU (which is Asus GT710 low profile), CPU fan, chasis fan). No luck.

- Continuity test seems alright and it appears nothing is shorted. Test random power pins with ground pins.

 

All the PSU test in this system still works fine, shorting the green cable with black cable activates the PSU. Voltage output seems still in range.

 

Visually inspecting the motherboard seems okay, no capacitors bulged (But hard to tell since this surface mount cap doesn't really bulged if its dead).

 

Anyway, if you can think of something, let me know. I'm still in the process of checking things.

 

Regards,

Chiyawa

[Convictions]

What do you mean that it seems to switch the PSU off and then on? What's happening?

[hardwin82]

3 hours ago, Chiyawa said:

The issue right now is when the system start, it seems to switch the PSU off then on then off then on again.

sounds like there is a problem with BIOS settings

checked things like CPU and memory settings

does your BIOS holds date?

[Chiyawa]

3 hours ago, Convictions said:

What do you mean that it seems to switch the PSU off and then on? What's happening?

It means the PSU goes on, and then off, and then on, and then off, and then on, and then off, and goes on... The transition between on and off happens about one seconds.

[Chiyawa]

1 hour ago, hardwin82 said:

sounds like there is a problem with BIOS settings

checked things like CPU and memory settings

does your BIOS holds date?

I did try to reset the BIOS to the motherboard, but to no avail.

[Convictions]

9 hours ago, Chiyawa said:

It means the PSU goes on, and then off, and then on, and then off, and then on, and then off, and goes on... The transition between on and off happens about one seconds.

How can you tell that it's the PSU that's power cycling?

[Chiyawa]

On 1/8/2021 at 3:39 AM, Convictions said:

How can you tell that it's the PSU that's power cycling?

Because the PSU fan spins up, and then down, and then up, and then down. Volt meter also shows the voltage goes up, and then down, and then up and so on...

 

That is when the PSU attached to the motherboard. When the PSU removed and manually powered up (by shorting the green cable to a black cable), the PSU works fine.

 

Anyway, it seems further troubleshooting confirms it's the motherboard that causes the issue. However, I don't think I ever come across this issue before.