Question My PC rarely starts up in my house, but in repair shop it starts fine ?

[xCJ11]

Ok pls hear me out , my pc rarely starts up in my house , but it does start up at random times but apparently in the repair shop it turns on perfectly and he took 10$ from me although idk what repair he did, and in my house it doesn't turn on or maybe it's a coincidence I'm not sure. I really don't understand what is wrong.

Specs:
Mobo: Asrock b450 Steel Legend
CPU: Ryzen 5 3400G
GPU: Asus Tuf GTX 1650
PSU: Zalman wattbitt 500w 83+
RAM: 2 x 8GB Hyperx Fury RGB

The motherboard has some led lights around the chip cooler and one of them is red ( I didn't change it ) , maybe it's some light malfunction? Because this board never came with diagnostic lights as far as I know. Any help would be great.

 

[helpstar]

what exactly was different between the repair shop and your home setup.

keyboard, mouse, monitor and video cable were identical?

what exactly happens while not booting? just a click, or do the fans spin up or not, drives spin up or not, monitor gets a picture or not?

 

[xCJ11]

what exactly was different between the repair shop and your home setup.

keyboard, mouse, monitor and video cable were identical?

what exactly happens while not booting? just a click, or do the fans spin up or not, drives spin up or not, monitor gets a picture or not?

It doesn't work, no lights , fans don't work ,no signal , nothing but the motherboard lights r on , it sometimes works , sometimes doesn't idk why like rn it worked but probably if I shut it down and wait 10 min it won't turn on , Also I'm not sure if this is useful or not but the fans keep running after shut down so after shutting down from Windows I gotta press the button after the screen goes blank.
And no difference from the repair shop , they didn't use a display or mouse or keyboard, the aim was to just turn the pc on.

 

[helpstar]

get a different monitor and video cable, check a different video port of the GPU
check without GPU
check the power cable to the wall as well, sometimes these don´t fit well and have to be pushed very hard to be connected well.

 

[xCJ11]

I checked without gpu before and there was no difference, there's no problem with the gpu as it's fairly new.
The power cable is DEFINITELY connected well and the pc also reboots after like 20mins of usage in case it turns on ( no hot high temp detected )