[SOLVED] Red CPU Led error on ASUS ROG Strix B450-I after bios update

Oct 11, 2020
5
1
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Hi Everyone,

I am writing here in hope I could get some enlightment after I probably bricked my motherboard after updating the BIOS.

I had some issues with a monitor so I decided to do an overall driver and bios update since I never did so since I bought my components 2 years ago.

I downloaded and installed all updated driver for both my VGA (a NVIDIA 1070) and my mother-board (an ASUS ROG STRIX B450-I).
After installing all normal drivers from windows, I performed the required restart to complete the driver update, but I also took the opportunity to update the BIOS before the full windows restart (didn't think this might be an issue).

I started flashing the BIOS, and when the procedure was completed, the PC restarted itself but the video signal never came back to the monitor.

After waiting a while without any video appearing, I turned off the PC and opened it up just to notice that the EZ startup LED on the motherboard gets stuck to the red CPU one during boot procedure.
I tried a bit of everything wihtout much success.
I did try to reset the CMOS using the jumpers, and when that didn't help I also tried removing the CMOS battery and replugging it in without success.
I tried removing either of the 2 RAM banks I have but still same problem.
I tried removing the CPU to check for bent pins (though it wokred for 2 years before that so I was quite sure this wasn't an issue) and indeed no bent pins were there.

One interesting thing I found out, is that if I unplug the GPU, the booting LED gets past the red CPU one and just stops at the white LED related to the VGA. Is this something normal or might it mean that the VGA is having issues?

Unfortunately I don't have any other components to swap out and test for single failures.
I do suppose it might be a motherboard issue since it all died after an attempted BIOS update...

I am already thinking buying a new motherboard (might as well upgrade to B550) but wanted to write here first in case someone might give me some additional insight...

Thanks in advance,
disberd
 
Solution
What RAM slots are you using ?
What Exact RAM kit model do you have ?
I would put 1 RAM stick in slot A2 and clear the CMOS like this:
  • Unplug the PC (PSU).
  • Then press the Power Button for at least 30 seconds.
(the on board ROG LEDs will sometimes flash after 20-30 seconds to show that all power has been drained from the board).

- Use a flat headed screwdriver to short the CLR CMOS (CLRTC) Jumper (Touch both jumper pins with the screwdriver) for at least 15 seconds.
CLRTC jumper location can be seen on page 1-2 here:
https://dlcdnets.asus.com/pub/ASUS/...G/E14337_ROG_STRIX_B450-I_GAMING_UM_PRINT.pdf
  • Plug the PC back in.
  • Press the Power Button to turn the PC on.
  • Repeatedly...

DMAN999

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Ambassador
What RAM slots are you using ?
What Exact RAM kit model do you have ?
I would put 1 RAM stick in slot A2 and clear the CMOS like this:
  • Unplug the PC (PSU).
  • Then press the Power Button for at least 30 seconds.
(the on board ROG LEDs will sometimes flash after 20-30 seconds to show that all power has been drained from the board).

- Use a flat headed screwdriver to short the CLR CMOS (CLRTC) Jumper (Touch both jumper pins with the screwdriver) for at least 15 seconds.
CLRTC jumper location can be seen on page 1-2 here:
https://dlcdnets.asus.com/pub/ASUS/...G/E14337_ROG_STRIX_B450-I_GAMING_UM_PRINT.pdf
  • Plug the PC back in.
  • Press the Power Button to turn the PC on.
  • Repeatedly tap the DEL key
  • A screen should come up telling you to press the F1 key, do that.
  • Set the Optimized Default settings and Press OK (this is on the EXIT tab)
  • Save and exit the BIOS.
  • Tap the DEL key again to enter the BIOS and change any settings you want changed then save and exit again.
 
Solution
Oct 11, 2020
5
1
15
Thanks for your fast reply DMAN999,

I tried doing what you suggested again with no avail.
In fact, I already did try swapping out RAM and reset the CMOS both with the jumper method you described and by phisically disconnecting the CMOS battery (as suggested in the motherboard manual if the jumper method fails).

The end result is still the motherboard stuck with the red CPU led and no video signal appearing.

P.S. My ram is Corsair Vengeance LPX 3200.
The actual model number is CMK16GX4M2B3200C16 (2x8GB)
 

DMAN999

Dignified
Ambassador
I have a 2600 on an Asus ROG Strix B450-F (as my backup PC) and when I was OCing the RAM and CPU it would not boot (with DRAM light on though) and clearing the CMOS multiple times always worked for me.
So you might want to clear the CMOS a few times in a row and also try with just one RAM stick in slot A2 (2nd from the CPU).
 
Oct 11, 2020
5
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Thanks again,

Unfortunately I did try resetting many times the cmos and changing RAM between A1 and B1 (The A2 is not present on the mini ITX version) but nothing changes.
I wonder now if before changing the motherboard it might be better buy a cheap AM4 APU (athlon 3000g) to have something to rule out cpu and vga in a cheap setup. For 55 euros it might also be a decent investment for debugging in the future
 
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Oct 11, 2020
5
1
15
So I received the athlon 3000G this morning and tried booting up with it.
To my surprise, the system managed to boot fine.

I can not understand how I could break the CPU while performing an update...
Is it possible that the bios update broke backward compatibility with ryzen 2000 CPUs while creating compatibility to the 3000 series?
I am a bit skeptical about reverting to the previous version of the firmware because I would then lose compatibility with the current athlno 3000g and would be left without anyway to boot up the system if the CPU itself is indeed compromised..
 

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