Question Motherboard won't receive power

[Airborne92]

So my computer has been a pain honestly after a issue my power supply broke most of my computer and i have replaced everything but every motherboard I have been getting has not been receiving power at all, I have tested my power supply and it works but for any replacement board I have gotten it just... Doesn't turn on, no power whatsoever
At this point I am about to give up I have no clue why my PC won't boot up

Psu - 500 watt garbage
Newest Motherboard - gigabyte b450m dswhatchamacallit I don't know right now
Last 3 motherboards - msi b450m gaming plus

 

[rgd1101]

how did you test the power supply?

 

[Airborne92]

how did you test the power supply?

Hooked it up to my brother's PC and it booted up

 

[rgd1101]

and he have the same setup?

what is your full system?

 

[ridderdk]

Pretty much same problem here:
Brand new MB - Asus Prime B450M-A
ATX 12V PSU (Toughpower DPS G 550)
We're not talking boot problems, warning beeps or anything - just nothing whatsoever when front panel pwr button is pressed.
I've checked and double checked and triple checked PIN connectors to make sure the front panel cables are correctly attached - there really aren't that many choices.
24-pin pwr cable and CPU 8-pin pwr cable also correctly attached.

Worked with ancient Gigabyte MB hours before trying with the new MB.

I probably will need to take it in for professional service, but it would be great if anyone has any ideas.
Haven't tried putting the old MB back in, so can't say for sure that the PSU didn't somehow magically die.

 

[Airborne92]

and he have the same setup?

what is your full system?

Sorry for a late response but I just went with one last switch and low and behold it started working, and I'm still not quite sure what was going on then but it is working now so I guess I'm not gonna mess with it and see if it is reliable

and to answer what you were saying he had a more power demanding setup, I have a vega 11 included graphics processor while he had an actual graphics card alongside his processor