New PC worked perfectly, installed Windows, then suddenly shut off and now shows CPU debug LED
Posted by Scared_Bet1611@reddit | buildapc | View on Reddit | 8 comments
I just built a new PC with a Ryzen 7 7800X3D and MSI MAG B850 Tomahawk Max WiFi. The build initially worked perfectly. I got into BIOS, enabled EXPO, installed Windows 11, connected to the internet, and started downloading AMD Adrenalin. While doing that, the PC suddenly powered off completely as if the power cable had been unplugged. Since then, it won’t turn on properly. Every time I try to turn it on, all the fans spin up and stay running, but I get no display output, no keyboard initialization, and the motherboard immediately shows a solid red CPU debug LED that never changes. The monitor wakes up briefly, reports no signal, and then goes back to sleep. What confuses me is that the system was stable enough to install Windows and run normally before this happened. Has anyone seen something similar on AM5, and does this sound more like a motherboard, CPU, PSU, or BIOS issue? Any suggestions would be appreciated.
T2_daBest@reddit
Did you check the CPU and ram to make sure they're seated and not damaged. Check to make sure thermal paste didn't not leak out after heating. If that doesn't work they using a different CPU cable from PSU or plugging in both of your mobo has that option. Also try removing a stick of ram and try both by themselves.
Did you hear any noises when it shut down?
unusedmicrophone@reddit
My first idea is the PSU had a problem and I would start by trying to power it off completely and unplug from the wall. Be patient with booting speed, take into account the memory initialization may take a long time with Ryzen processors but that is an issue to solve later with BIOS upgrades.
Scared_Bet1611@reddit (OP)
Thanks, I tried this and same thing is happening.
unusedmicrophone@reddit
Next componentest I would check if they are well inserted: power cables, memory modules, cpu cooler.
Scared_Bet1611@reddit (OP)
Just checked everything’s seated well. I even unplugged everything and replugged.
unusedmicrophone@reddit
I can't think of anything else right now other than removing the BIOS battery for a while so it resets to its default settings. I hope your CPU is not damaged.
Scared_Bet1611@reddit (OP)
Okay, thanks so much for your help. Just wondering if the cpu was working fine previously is there a high chance it’s damaged?
unusedmicrophone@reddit
I never had a truly broken cpu. My current Ryzen gave me a lot of troubles with boot looping at the start and learned the diagnostic led lights may be confusing. In my experience with this computer and others, it is very rare to damage the CPU with overheating as they come with automatic protection measures like downclocking and shuttting off themselves.
More than once I booted my Ryzen computer and happened like yours, my only trick was inmediately press the power button down to forcefully power it off, the result is not the same as with the switch on psu or unplugging the power cord.