CPU debug light on MSI B450 motherboard - won't boot

[FinnMc26]

Hi,

So last week I built my first PC and it worked great for the first few days. I went away over New Year's and came back after a few days to the debug led failing on the CPU light which seems strange to me as the computer has not been touched since I left. I have an MSI B450 Gaming Pro Carbon motherboard and a Ryzen 2600X CPU.

I have tried unplugging and replugging the CPU power connector for the mobo and checked that it is plugged in at the PSU end. The GPU fans also power up and then stop as is normal for a boot and the CPU fan works fine.

I have also tried resetting the CMOS as motherboard showed using a flat head screwdriver instead of a jumper cab. I overclocked my RAM to 3000mhz and thought maybe the OC had become unstable. I also tried booting with only one stick of RAM in the DIMMA2 (second) slot on the motherboard.

There is one other red LED in the very top left of the motherboard next to the IO shield that has no label
Full parts list: https://nz.pcpartpicker.com/list/DmD3XP

Please help I'm not sure what's suddenly gone wrong in a build that was otherwise working perfectly.

 

[Lutfij]

Are both EPS connectors on the board, populated? You might want to breadboard the system and try using rams from a neighbor or friend. To rule out faulty memory. You can try and remove CMOS battery and replace ti after 15 mins and see if that changes anything.

Per your manual, the only LED's mentioned on the motherboard that are of Diagnostic aid are the CPU, VGA, BOOT and DRAM.

 

[FinnMc26]

Are both EPS connectors on the board, populated? You might want to breadboard the system and try using rams from a neighbor or friend. To rule out faulty memory. You can try and remove CMOS battery and replace ti after 15 mins and see if that changes anything.

Per your manual, the only LED's mentioned on the motherboard that are of Diagnostic aid are the CPU, VGA, BOOT and DRAM.

Yes I've tried the connectors with all 8 pins, only 4 pins, and CPU power slot 2 as well as 1. Nothing seems to be different there unless it's a faulty power cable. I've just taken the battery out so I'll leave it for a bit and put it back soon see if that helps.
Otherwise I'll stick in some old DDR2 RAM I have lying around from a rendering PC and see if that is the fault.

Hopefully something here helps otherwise I guess it could be a faulty PSU cable maybe even the CPU though that is unlikely right?

Thanks for your suggestions

Update: The battery removal didn't work after leaving it for over an hour. I'm thinking that there might a be faulty part. Thing is The computer won't boot with even one of the RAM sticks in so it seems strange that both DIMM's would develop a fault at the same time? Makes me think that it's more likely to be a PSU or CPU fault... would it be worth taking the CPU and cooler off to see if anything is the problem there?