Question Random EZ Debug Red CPU LED On Boot

Dec 20, 2019

I recently built my 1st ever PC and was very proud off myself as everything seemed to be working fine. I thought too soon.

Every, say, 1 in 8 boots from shut down, the Red CPU EZ debug LED comes on and stays lit as the PC begins to boot into Windows 10 and then the PC shuts down.

However, I then do a hard reset by holding power button on case down, leave it a few secs, and then turn power switch back on and the PC boots into Windows normally without issue and runs fine.

Other, information is that last night my PC did suddenly turn itself off whilst I was browsing on Chrome but rebooted back up without issue. Event viewer has also thrown up some issues around unexpected shutdowns and not complete shutdowns.

The only other relevant info I can think off is that I had to patch the bios on my RX 570 as it was bought from Amazon Warehouse and looks like it was modified for mining and windows couldnt recognise it or the drivers without the patch being applied.

Any help that can be offered to save my 1st ever build would be massively appreciated.



MSI B450M Mortar
16gb Crucial Ballistix 3000 RAM
Ryzen 5 2600 with Deepcool Gammax 400 cooler.
Sapphire Pulse Radeon RX 570 4gb (used)
EVGA 80+ Gold 550W Supernova G2 or G3.
2 front 120mm intake fans, 1 120mm exhaust case fan.


If the OS doesn't know that it's failing, which seems to be the case from event viewer, you may have a power issue on your hands. EVGA G3s are NOT very good.

Do you have a spare power supply (or one you could buy and then return) to test with?
Dec 20, 2019
Thanks for the help.

I am going to order a new power supply and try that first. Would 650w be enough? I went with 550w as pcpartpicker said that was enough. I have googled and found users with similar symptoms to mine who had it resolved it with a new power supply. Something about "Bugcode+0" hinting at it and a "spike" causing issues like if it spikes there isn't enough power? Sorry, thats off the top of my head as can't find the post again.

Is there any test or software available that can definitively tell me whether my specific power supply is providing enough power or not and/or prove if the power supply is the issue?

I ran Memtest for passes and it took over 3 hours to complete and found 0 errors. Does that mean I can rule that out or do I need to re-seat it?

Finally, when installing my CPU I had an issue that when the lock lever was pulled down the CPU sprang up ever so slightly but still felt secure. However, I had a terrible time fastening the cpu cooler whilst trying not to smudge thermal paste everywhere and at one point when I lifted the cooler up to start again the CPU came out of the socket stuck to the contact plate of the cooler due to the paste.

I couldn't see any damaged pins on inspection but my eye sights not the best and I didn't have a magnifying glass. The CPU reseated easily when putting it back in and I finally got the cooler on. Thermals haven't got above 40oC yet as I haven't done anything other than watching Youtube and internet browsing.

Do ou think I should continue with getting a new power supply and see if that fixes it? I can always send it back if it turns out to be something else.

Many thanks for your help and time.
Dec 20, 2019
Hey everyone,

I have replaced the power supply with a Corsair 750W 80+ Gold and the problem described above is still occuring.

So if not the power supply what would anyone suggest investigating next? My gut instinct is the CPU since the computer freezes for a few seconds, then goes to a black screen at the exact same time the CPU debug light comes on on the Mobo. Everything else stays on (LEDs, Case fans, CPU cooler, Case lights etc) but there's just a black screen on the monitor until the monitor auto powers itself to sleep.

Please can anyone give some further advice as I'm at a loss to how to diagnose the faulty hardware and its getting expensive as I can't afford to replace each part to do a trial and error diagnostic on parts and I don't have any access to spares for testing either.

Thanks in advance.