eventful experience pc giving no signal

specs:
Gtx 4070 ti super
Ryzen 7 5900x
B550M Aorous Pro (old mb)
B550M Gaming X Wifi6 (new mb)
750w power supply

yesterday playing a game my pc abruptly turned off and wouldn't turn back on, left for a few hours no luck.

I swapped out the power supply to an older (weaker) one i had to test and upon starting the pc instantly began smoking and i heard a crackling sound around the motherboard, not entirely sure what smoked tho, but began instantly when power was applied. Could find no melting / burning on any components.

swapped back to main psu and psu /case fans worked when atx was in and cpu 8 pin was out, but no power would be applied when cpu 8 pin was in simultaneously

assumed the motherboard was bad, bought a new one and threw everything back in and pc starts and sounds like normal, but there is no signal on the screen and peripherals are not being lit up.

already tried:
- re sat ram, cpu, gpu
- swapped out ram for different type
- removing cmos battery
- ensured all cables are plugged in correct