Hi everyone. I keep getting QCode 64 and boot loop after I update to bios 0904. When I roll back to 0816 the machine boots fine. I have tried unplugging everything (USB devices etc.), reseating the RAM, trying one stick of RAM in each DIMM slot ((did that with both sticks)), removed the sound card. I am unsure what is causing it or if it's just a dodgy bios. I have downloaded it a couple of times to hopefully ensure it's not corrupted but that didn't work either. My machine is as follows.
ROG Z790 Hero
32GB Kingston Fury 5600 - KF556C36BBEAK2-32 (I have a feeling this is not on the QVL and might be the root cause of the issue, if someone can verify this is likely my problem, I would appreciate it).
If you need to know anything else or I've missed anything important, let me know.
Solved! Go to Solution.
For B4 loop issue, please follow these instructions. Please make sure to follow these correctly and remove any internal USB headers.
1. Update ME Firmware to 126.96.36.1996 and reboot.
2. Remove all USB devices and internal headers from the system
3. Turn the system off and remove the AC (Unplug the PSU and wait 30 seconds)
4. Turn on the AC. Flash to 1303 using USB Flashback
5. Once the flash is completed check behaviour. If still stuck looping remove AC (unplug PSU) once again and wait 10 seconds. Then reattempt boot.
Briefly looking online, I think 64 pertains to a potential USB peripheral issue? You could try to minimize your USB peripherals, or try other ports, try other mice or keyboards. Maybe the new BIOS doesn't like one of them! lol.
I personally had ram instability and program/PC crashes after updating to 0904. On 0816 BIOS was mainly stock, with XMP I with ram off the QVL running stable at the 7200 speeds. 0 issues. Updated to 0904 BIOS, enabled XMP I, changed next to nothing, and then had PC crashes, programs randomly closing. Went back to 0816 with XMP I enabled and haven't had a crash since!
There may be more to it for my case, but hopefully this helps you check a few things. There was some talk of 0904 on this forum ((1) [OFFICIAL] Asus Strix/Maximus Z790 Owners Thread | Page 332 | Overclock.net) - it seems like some users had issues, and some didn't. Some also knew a LOT about ram settings in BIOS so I'm sure they can easily get stability, whereas I want to keep it simple with selecting XMP I. I don't think I will benefit from 0904 for my set up at this time. I have no pressing issues or requirements to need to update. I do want to continue to update my BIOS, but not if I have issues for what I'm running.
I'm skipping 0904 and waiting for the next one and will wait for others to test. I was the guinea pig for 0904.
Thanks Vinny, I literally unplugged everything. Only thing inserted was the video card and one stick of RAM at one point. If I had the 13900k instead of KF I would of pulled the card out too. I also think code 64 on this board relates to DXE in the manual code 63 to 67 inclusive relates to this and that is written to the RAM just before the OS sequence begins. I have a funny feeling it's a RAM issue I just can't be certain as I don't have other RAM to test. I think I will be doing the same as you and waiting for the next bios update. Thanks for your help.
I really hope someone else has the answer for you. As you reference in your first post, I'd check against the latest QVL for your ram. If ram is not on the QVL, it's compatibility may fluctuate between BIOS updates, so maybe it's truly not on the QVL for a reason that's way out of my knowledge haha.
All I really wanted was to feedback on 0904 being unstable for my case as well as anything that first came to mind to check, so it could just be a dud of a BIOS update, or someone else will swoop in with the details we're overlooking. Best of luck!
Have you made any changes to the Bios from their default settings?
I don't have the KF version of the CPU and my system is still stable. I did check for "CPU DXE" and there were quite a few threads addressing this situation.
If you were seeing something around 55, I might agree with the memory situation since I have seen that.
Hi Salt, thanks for your answer. I did try loading optimized defaults before updating the bios. That solution also sis not work. One thing I noticed is when it gets to 64 on the qCode display, it flicks to another number about 3 times before it reboots, the flick between 64 and the other number is so fast I can't actually see it. I'd need some super slow no camera David Attenborough uses or something. I wasn't able to find any information on people having DXE problems on this board, older boards yes. Do you have a link to an issue with this board? Thanks again for your reply.
The other thing to watch are the 4 LEDs that go in sequence during boot. The red (CPU) is on initially then it goes to the memory (amber), video (white) and then boot (green). When the Green (Boot) light turns off, it is booting Windows.
I am not seeing the CPU situation on my board. You might also run the command below and check the graph to see if anything is showing on a regular basis.
Hi. I'm also getting a continuous boot loop on BIOS v0904 where POST never completes before it loops. I haven't had this problem on previous BIOS versions. Happens with all USB devices disconnected. And for what it is worth, my RAM is on the compatibility list. (Corsair CMT64GX5M2X5600C40).
I fixed it by rolling back to v0816 using the BIOS FlashBack function.
v0904 clearly has problems. I'm going to wait for the next version and see what happens then.
Hi Bernard, thanks for your contribution to the post. I appreciate you letting me know you have the same issue with RAM that is on the QVL. That makes me feel slightly better. I did the same as you and disconnected everything except the video card at one point and it still didn't post. So, it's nice to know I'm not the only one.