Question M.2 woes

[jazmag]

R5 3600
Asus prime b550
HP Rtx 3060ti
Crucial p3 plus 1tb
Corsair vengeance lpx 16gb ddr4
Corsair tx550m

This is my son's system and not long ago he started getting blue screens until the system just loaded into bios and stopped recognising the m.2 I troubleshooted and RMA'd the motherboard. They sent a new one however now I can't get it to work with an m.2 Installed. I can get in to bios with no storage devices however with an m.2 (tried multiple) installed I just get no signal on the monitor. To get the system to post again after trying an m.2 I have to clear CMOS.

Tried:
CSM is enabled,
ERP is set to S4+S5
No overclocking
All components work in other systems

Tried an older GPU and it posted. For some reason the b550 doesn't like the 3060.

 

[Lutfij]

Corsair tx550m
How old is your PSU in this build?

Asus prime b550
Asus have a couple of B550 chipset motherboards under the prime series, which one do you have? If you're able to get into BIOS, what BIOS version are you currently on for your motherboard?

Speaking of motherboard's, were you given a like for like motherboard or was it an upgrade?

 

[SkyNetRising]

Asus prime b550
I can't get it to work with an m.2 Installed.
Tried an older GPU and it posted. For some reason the b550 doesn't like the 3060.

Which exactly Asus B550 model?
Does it have multiple M.2 slots?
Did you try M.2 drive in all M.2 slots available?

Update BIOS to latest version.
Try forcing PCIE to gen 3.0 mode.