Question Power button problem possibly

[FRoob]

I have a Fractal Design Define R3 case. It's about ten years old. I'm wondering if there could be a problem with the front power button?

If I switch the PSU mains power on and then press the case power button, the red light at the front of the case lights briefly and then goes out. Nothing else happens. Before I can try again, I have to switch the mains off to the PSU and back on again, but the result when pressing the front case button is the same.

I suspected the PSU, but changing that (brand new Corsair RM750x) and it made no difference. I've since changed the motherboard (Asus Prime B450M-A running a Ryzen 5 3600).

It had been working fine for a couple of years and then one day it refused to power up as described above.

Is there a relay of something in the case power button or something else that might have stopped working? Apart from trying a different case, is there any way of trouble-shooting this, with regard to the case button? The only other thing left to swap out is he CPU but I thought I'd ask about the button first.

Thanks.

 

[Lutfij]

To come to the conclusion that the front panel button is what's causing the issue, disconnect it from the motherboard, then short the pins on the motherboard. For context, it's a good idea to pass on your full system's specs. Since you performed a couple of upgrades(or replacement) a before and after specs would be a good idea.

I had a similar front panel power button issue with my Special Edition Phanteks Enthoo Evolv itx(the first one). I lost the power button, then I used the reset button as the power button, then that failed. made me think that the system was suffering from a grounding issue. Removed the front panel buttons from the equation, shorted the power pins(and later the rest pins) and then realized the physical button on the case were the culprits. I sourced some tactile momentary switches with the right dimensions(using a sliding caliper) and soldered them back.

 

[FRoob]

Ah - you responded to my post on the motherboard forum a little earlier, thanks.

Here's the before:

Asus Prime B450M-A motherboard
AMD Ryzen 5 3600 CPU and stock cooler
2x16GB DRAM
Zotac GTX970 GPU
Fractal Design Define R3 case
EVGA 750Gq 80 PSU

(all disks and other peripherals apart from keyboard and mouse, disconnected)

I actually had to make do with an Asus Prime B450M-KII replacement motherboard as it was difficult to source the older B450M-A version. The only difference is that it's slightly smaller and only takes two RAM modules.

The replaced PSU is a Corsair RM750x.

Can I provide any other info?

 

[FRoob]

I've now swapped the power and reset connections and I can replicate the behaviour via the reset button. Also shorting the power header pins does the same thing so it's not the power button.

I don't have access to a known working motherboard to test the CPU, so I guess I will have to consider buying a replacement CPU.