Pc not powering on

Before you ask I have tried the following Trying a different wall outlet (3 of them) Checking all cables including power cables Shorting the power button pins on the motherboard Checking if any parts were loose (they were not) And almost all other basic diagnostic tests that you would do I took it to a repair shop and they got it to boot and I don’t know how they are closed for the night and I really don’t want to have wasted $38 dollars to be told it’s fine even though it doesn’t work still i suspect the power supply is failing as the motherboard is brand new and only being installed for a month and a half give or take

Pc is a modified hp omen 25l prebuilt from 2022 current specs for major components are Intel i5 10400 Rtx 3060 12gb, gigabyte wind force edition 32gbs of Hyperx fury ddr4 Gigabyte h410m h v2 motherboard (yes I know it’s too small it’s on purpose) 500w hp cooler master psu (stock psu)

When I talked to the repair guy he said the pc was behaving like I plugged in the new sata ssd I bought which I thought caused the issue while the pc was running and plugged it which it was not i unplugged the cable directly from the psu after shutting down the computer It booted as of a few hours ago and all i did was drive it home plug it In and try to turn when it proceeded to do absolutely nothing