No Fan Spin - Power Switch?

[aj0312]

Hi,

 

ASUS PRIME B320M-K mobo

i7-6700k

Samsung Pro 850 M.2 drive

AMD RX470 GPU

Corsair 450V PSU

 

I recently posted about a faulty mobo that I replaced as per advice on this forum and IT WORKED! However, I'm back on the forum

 

The new motherboard worked fine for a while now, but in order to turn the PC on I had to short the power switch on the motherboard with a screwdriver. The power switch on the PC never worked. Now, even the screwdriver trick won't work, so I have a unresponsive PC. What should I do? The PC was fully operational in the mean time, now I get no power at all other than the mobo lights.

 

Do I need to buy another mobo? Is there another power switch trick I could try? I have a spare PSU that I could try to eliminate PSU error

 

Thanks for any advice,

 

[aj0312]

as expected, the other PSU does not change anything.. so the likely culprit is the mobo. Are there any good techniques to switch the PC on (other than shorting the pins on the mobo with a screwdriver)?

[Duckster]

5 minutes ago, aj0312 said:

as expected, the other PSU does not change anything.. so the likely culprit is the mobo. Are there any good techniques to switch the PC on (other than shorting the pins on the mobo with a screwdriver)?

Have you connected the power button with the mobo?

[aj0312]

Hi Duckster,

 

Yes I tried the following:

 

Ensured the power button headers were in correct order on the motherboard pins

shorted the motherboard pins with a screwdriver (worked, but now doesn't)

 

So I'm wondering if there is another method I could try before ordering a new mobo

[Duckster]

2 minutes ago, aj0312 said:

Hi Duckster,

 

Yes I tried the following:

 

Ensured the power button headers were in correct order on the motherboard pins

shorted the motherboard pins with a screwdriver (worked, but now doesn't)

 

So I'm wondering if there is another method I could try before ordering a new mobo

mind sending me a photo?

[greenhorn]

4 minutes ago, aj0312 said:

Ensured the power button headers were in correct order on the motherboard pins

shorted the motherboard pins with a screwdriver (worked, but now doesn't)

That is very strange. The power button is a simple switch that shorts the two contacts when pushed, so it should have the exact same effect as the screwdriver when working properly. Do you have a multimeter lying around (or know someone who can lend you his/hers) and use the continuity check function to test the power button itself?
I know it may sound weird, but I have already seen a computer with a malfunctioning power button before (in that case the contacts were permanently shorted which turned the PC off immediately).
If the power button is fine, then it gets more complicated, motherboards just don't die like that, especially two in a row in such a short time span. The next possible culprit could be the power supply (if the voltages are way off and damage the board for example).

[aj0312]

I have already taken the mobo out of the case for testing, I've attached some pics of the striped down PC.

 

I am buying a multimeter tomorrow to see what the voltages are like.

 

I have tested with 2 known working PSUs, so I really doubt there is a problem there. The previous mobo died because I ripped out an old gpu with the power still on (oops! lesson learnt!)

 

As you can see the light on the mobo is on (orange to the left of the second pic), but when I put the screwdriver between the + and - of the power switch there is nothing

 

[aj0312]

UPDATE

 

Tested with the multimeter (shown in attachement). 6.4V across the 2 pins. Does this give anycleus are to why the PC won't switch on?

 

I'm a complete beginner with these things so please let me know if I have done something incorrect, the chances are very high that this is the case.

 

Thanks for any comments,

Alex

[aj0312]

@greenhorn

 

Do you have any tips for me?

[greenhorn]

On 5/7/2019 at 4:47 PM, aj0312 said:

@greenhorn

 

Do you have any tips for me?

Hi,
sorry for only responding now, I did not get any notification for some reason.

Your multimeter shows you measured the AC voltage, but in this case the DC voltage is more relevant (set the multimeter knob to the 20V range to the left of the "OFF" position and measure again).