Question PC turns on, then No Signal. Strange EZDebug LED sequence.

[Doubel]

Context:
Built this PC 2 years ago. Problem started happening 2 weeks ago. When I turned on my PC, an underscore would show on screen for half a second before all of my peripherals turned off (mouse, keyboard), only to turn back on 2 seconds later. I would be stuck in an infinite loop of this before having to manually hold down the power button. I've tried the hard power button reset, where I hold the power button for 20s while the PSU is switched off and the adapter is unplugged: didn't work. I tried a USB flash bios with the latest mobo version, and then it said click F1 to load setup or F2 to run to load default values. I clicked F1, loaded optimized defaults, click saved and reboot, and then my PC booted up to the windows login screen. Right as I clicked login, peripherals turn off and now I'm back at the same problem. Only this time, instead of the infinitely repeating underscore/peripheral boot loop, the peripherals don't turn on at all. I'm just left with the PC on.

At one point, it was either when I reseated CMOS, flashed bios, or reseated RAM, I was able to get to the bios splash "Arsenal Gaming". Then 10 seconds pass, I get "No Signal" on the monitor, and the peripherals turn off as seen earlier.

I did notice that the EZDebug lights were flashing in this sequence:
VGA - 0.5s
CPU - 3s
All LEDs off - 3s

And that continues to infinitely loop. In most posts I see, the CPU led just remains on rather than flashing in this sequence. Whether or not that makes a difference as to indicate what kind of CPU problem it is - I'm not sure. But I just thought it was worth mentioning, as based off the previous forum posts I've scoured related to this, there is likely a problem with the CPU/PSU. Still hoping that there's some way to fix it before having to resort to part replacements.

Specs:

• AMD Ryzen 7 2700X Processor with Wraith Prism LED Cooler
• MSI AM4 ATX B450 Tomahawk
• 16GB (2x8) G.Skill Ripjaws V Series DDR4 3600 Mhz 1.35V CLS 16-19-19-39
• Gigabyte GeForce RTX 2060 Super Rev 2.0
• Sillicon Power 256GB M.2 PCIe
• Seasonic S12III 80+ Bronze 550W
• Seagate BarraCuda 2TB 7200 RPM 256MB Cache
• Fractal Design Focus G Mid Tower ATX Case

 

[Lutfij]

Welcome to the forums, newcomer!

Seasonic is the brand of the unit while S12III is it's series, you will need to parse the wattage of unit. For the sake of relevance, what BIOS version are you working with on your motherboard at the time of writing? Sometimes a CPU's memory controller might give out or that the CPU itself gives out. Sometimes it's the BIOS that ends up playing tricks on the system.

 

[Doubel]

Welcome to the forums, newcomer!

Seasonic is the brand of the unit while S12III is it's series, you will need to parse the wattage of unit. For the sake of relevance, what BIOS version are you working with on your motherboard at the time of writing? Sometimes a CPU's memory controller might give out or that the CPU itself gives out. Sometimes it's the BIOS that ends up playing tricks on the system.

Hello. Sorry, could've sworn I already had the wattage copied on the speclist, guess not though. It's a 550W PSU, and the mobo currently has GSE Click Bios 5 version 7C02v1E installed on it.