[SOLVED] Built new PC, will no longer output after two successful boots, CPU debug light now flashing

[TabrisThe17th]

The problem
I have just built a new PC, and initially it launched just fine. I entered the BIOS menu and checked that everything was detected, which it was. I went to flash the BIOS by launching in M-flash mode but it didn't detect the new BIOS file on my thumb drive, which was fine because I knew I might have saved it incorrectly, so I rebooted back to BIOS. When back in BIOS I loaded the X-AMP profile for my RAM and restarted again.

Except after restarting there was no longer any output, and when I checked the motherboard the ez debug CPU light was flashing red. I don't know if it did this on the first two boots (though I doubt it).

Troubleshooting
I tried different RAM configurations (2x8, 2x8 swapped round, 1x8 with both sticks, double checked they were in the correct position) to see if that made a difference - it didn't.

After this I removed the mobo from the case entirely, reseated the CPU, and booted it again with just the CPU, CPU cooler, and RAM (I also switched to the default Ryzen air cooler because I couldn't connect the h100i outside the mobo). Same problem.

It immediately goes to the red CPU light, and there's no output via the GPU Display port or the mobo HDMI. I also couldn't get anything to light up on the keyboard when I pressed num lock.

Other possible issues/explanations
I noticed a piece of metal from the IO shield did not slot in properly and was in contact with the ethernet port.

The CPU cooler was making sounds that might have been unusual, though I haven't heard a water cooler before. You could clearly hear the water moving through the pipes, and after breaking this was no longer audible, however I have checked and there are no water leaks.

I did not wear a grounding wrist strap and sometimes touched the motherboard whilst plugging things in.

Specs
Mobo: MSI x570 Gaming Plus
CPU: Ryzen 3700x
CPU Cooler: Corsair h100i water cooler 240mm
GPU: ASUS GTX 1660ti
RAM: LPX Vengeance 2x8GB 3200mhz
PSU: Thermaltake London 550w Gold

UPDATE: I removed the CMOS battery and flashed the BIOS before initialising X-AMP, and now everything works. It looks like something was off with the way the base BIOS handled memory.

 

[Lutfij]

Yeah, that PSU should not be purchased in the first place. Replace that unit for something more reliable, at the very least a Corsair CX550M unit or a Seasonic built unit with at least 500~550W of power at the entire system's disposal.

Did you try and remove the CMOS battery from the board and replace it after 30 minutes?

To note, you will need to have the BIOS file on a FAT32 formatted USB drive in order for M-Flash to recognize the BIOS file in order to flash to the latest version.

 

[TabrisThe17th]

Removing the CMOS battery worked! Everything is working now that I reset the BIOS and flashed it to the latest version.

Yeah, that PSU should not be purchased in the first place. Replace that unit for something more reliable, at the very least a Corsair CX550M unit or a Seasonic built unit with at least 500~550W of power at the entire system's disposal.

Is this PSU really that bad? I could get a new one but after setting everything up finally I'd really rather avoid rewiring the entire computer if I can.