MSI B450 Gaming Pro Carbon AC - no POST after BIOS flashback

DragonQ

DragonQ

DragonQ

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I have performed a BIOS flashback on a brand new MSI B450 Gaming Pro Carbon AC motherboard using the official instructions. It appears to work fine - the LED flashes for 5 minutes then stops, the motherboard resets itself and then just sits there doing nothing. The first time it did this I waited a good 10 minutes before powering it off and on.

Once I've power cycled the board, I am greeted with a "new CPU, configure BIOS" message. I go into the BIOS and do "save and reboot". Now the system refuses to POST at all and the CPU debug LED immediately comes on and stays on when I turn on the power. Clearing the CMOS doesn't help. The only way I can get back into the BIOS is to do a fresh BIOS flashback, but every time I do this, enter the BIOS and reboot, I get stuck with no POST, no monitor, no USB, nothing, and a red CPU debug LED.

I know the CPU (R5 3600) is fine because I tested it in another machine beforehand. Also, I have at least gotten to the BIOS a couple of times.

Any ideas?
 
There seem to be many people suffering from similar problems on the MSI subreddit:
https://www.reddit.com/r/MSI_Gaming/

Title of this one is for a different motherboard than yours, but MSI acknowledges there's a problem and does mention all their 3rd gen Ryzen compatible boards:
https://www.reddit.com/r/MSI_Gaming/comments/ce3ift/msi_b450_tomahawk_update/
Our BIOS team is working very hard to release stable BIOS versions for all motherboards compatible with Ryzen 3rd gen processors. Please understand that this is no easy task especially for so many models, and is certainly not as simple as copy/pasting code. We estimate that new BIOS with the new AGESA will be released closer to the end of this month for most board models.
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I've read about a couple of potential workarounds, but no idea if either of these work:
1. Don't enable XMP settings.
2. Disconnect case's reset button from motherboard pins.
 
Journey said:
Sounds weird, the fact you can actually get in to the BIOS and then errors on the next boot. Have you altered any settings in the BIOS while it was working the first time?
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The first time I got to the BIOS I changed settings because I thought everything was fine. Other times I've gotten into the BIOS (i.e. immediately after flashes) I have just left it at default settings and it always fails to POST on subsequent boots. Even clearing CMOS doesn't help so I'm sure it's not a settings issue. It sounds like the BIOS is just bugged, despite the fact that the website says it supports Ryzen 3000 and isn't even a beta release.

I've also tried the older version 7B85v16 from March (release note just says "Support new upcoming AMD cpu") and that one doesn't POST at all.
 
DragonQ said:
The first time I got to the BIOS I changed settings because I thought everything was fine. Other times I've gotten into the BIOS (i.e. immediately after flashes) I have just left it at default settings and it always fails to POST on subsequent boots. Even clearing CMOS doesn't help so I'm sure it's not a settings issue. It sounds like the BIOS is just bugged, despite the fact that the website says it supports Ryzen 3000 and isn't even a beta release.

I've also tried the older version 7B85v16 from March (release note just says "Support new upcoming AMD cpu") and that one doesn't POST at all.
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You don't happen to have tried a single stick of RAM on first boot, and the subsequent boot after that?

I've done two Pro Carbon AC's in the past week, and three in total and I'm yet to have one that doesn't work.

My method for flashing was:

1.) Empty board, no CPU or RAM installed.
2.) Flash drive loaded with only one file MSI.ROM (http://download.msi.com/bos_exe/mb/7B85v17.zip)
3.) Flash board, power down system and unplug from the wall.
4.) Install CPU with cooler and RAM, plus GPU etc. (Slots 2 & 4 for RAM)
5.) Plug system back in with all Front Panel headers connected correctly.
6.) Turn on system, allow 15-40 seconds for first POST
7.) Enter BIOS via F1 message, and check all of the setting are as expected but not altering anything.
8.) Insert flash drive with Windows Installer, install Windows 10 1903.

That was it, has worked every time.
 
Journey said:
You don't happen to have tried a single stick of RAM on first boot, and the subsequent boot after that?

I've done two Pro Carbon AC's in the past week, and three in total and I'm yet to have one that doesn't work.

My method for flashing was:

1.) Empty board, no CPU or RAM installed.
2.) Flash drive loaded with only one file MSI.ROM (http://download.msi.com/bos_exe/mb/7B85v17.zip)
3.) Flash board, power down system and unplug from the wall.
4.) Install CPU with cooler and RAM, plus GPU etc. (Slots 2 & 4 for RAM)
5.) Plug system back in with all Front Panel headers connected correctly.
6.) Turn on system, allow 15-40 seconds for first POST
7.) Enter BIOS via F1 message, and check all of the setting are as expected but not altering anything.
8.) Insert flash drive with Windows Installer, install Windows 10 1903.

That was it, has worked every time.
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I did try moving the RAM sticks around and trying only one at a time, etc. but it didn't help. I seem to have made some progress though!

I tried flashing the older BIOS (v16) then once it had finished it just sat there confused. I then flashed the newer BIOS (v17) and it finished then booted straight to Windows! This is the first time it's done this, every other time I've flashed BIOS (v17) it's asked me to go into the BIOS.

I then rebooted and went into the BIOS, changed one random setting and did a "save and exit". The board was stuck again. I power cycled it and got back into Windows. I went back into the BIOS and confirmed the setting change had been remembered. I then enabled XMP, saved and exited, and it was stuck again. Power cycled it and it got back into Windows.

In summary, it seems like going into (or more specifically, leaving) the BIOS results in the board getting stuck. Flashing the older BIOS first allowed the board to boot without needing to go into the BIOS, hence it seems to work.

EDIT: So far, every single reboot whilst trying to install a fresh copy of Windows has failed. Every time I have to press the reset button on the case to complete the reboot. :(

an0nym0us said:
2. Disconnect case's reset button from motherboard pins.
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I might try this because (a) I've heard that trick before, (b) it definitely seems to have issues restarting from the BIOS.
 
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This is a really common problem, coming up a lot on Reddit, MSI forums, and some other tech forums I post in too. Very strange that it's affecting some people and not others.

I personally have a B450M Mortar and had zero issues with it updating and booting, thank god.
 
DragonQ said:
Irrelevant. Happens at stock or XMP.
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I'd hardly say it is irrelevant, I've had similar issues due to the RAM voltage either set to low, or droop causing instability when the board is trying to post with that speed or the auto timings. It could also be the SoC voltage that is causing it.

There was a good reason for asking.
 
DragonQ said:
I did try moving the RAM sticks around and trying only one at a time, etc. but it didn't help. I seem to have made some progress though!

I tried flashing the older BIOS (v16) then once it had finished it just sat there confused. I then flashed the newer BIOS (v17) and it finished then booted straight to Windows! This is the first time it's done this, every other time I've flashed BIOS (v17) it's asked me to go into the BIOS.

I then rebooted and went into the BIOS, changed one random setting and did a "save and exit". The board was stuck again. I power cycled it and got back into Windows. I went back into the BIOS and confirmed the setting change had been remembered. I then enabled XMP, saved and exited, and it was stuck again. Power cycled it and it got back into Windows.

In summary, it seems like going into (or more specifically, leaving) the BIOS results in the board getting stuck. Flashing the older BIOS first allowed the board to boot without needing to go into the BIOS, hence it seems to work.

EDIT: So far, every single reboot whilst trying to install a fresh copy of Windows has failed. Every time I have to press the reset button on the case to complete the reboot. :(


I might try this because (a) I've heard that trick before, (b) it definitely seems to have issues restarting from the BIOS.
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I've got the same issue with the same mobo (B450 Carbon AC) and CPU (R5 3600) comibination as you.

I managed to do the BIOS flashback without the CPU and RAM installed without any issues (v17 beta).

I have not been able to get the system to boot properly after a restart, whether it's from Windows or by saving new settings in BIOS. It just gets stuck until a hard reboot is performed (power off, back on cycle).

This is the same with the XMP profile enabled or default RAM settings. I have not got the reset switch plugged in to the mainboard, only the power one.

No problems in Windows other than the above.

Let me know if you find a solution to the problems. I reckon we'll need to wait until the new BIOS is out towards the end of the month.
 
Journey said:
What hardware revision are your boards? It is printed on the board between the two 16x PCI-E slots. Should read MS-7885 VER:1.1.
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It's a shame that everyone with this issue hasn't included a full system spec including motherboard revision, as I suspect it would help in narrowing down what the exact issue is.
 
I was having precisely the same problem as you with the same CPU and Mobo. I eventually gave up and RMAd my board and told the supplier I didn't want it back until it was pre-flashed with a working bios and tested to be working correctly. They sent a brand new replacement board (pre-flashed with the V17 non-beta bios) and everything worked first time.

I went through all the ballache you did with clearing the CMOS and reflashing to no avail. Unfortunately I can't help much other than to recommend you RMA your mobo and ask for a replacement. It's a pain in the arse but it worked for me. Seems like you just have to get lucky with the motherboard.
 
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