MSI (MAG TOMAHAWK) Flash Button - What the manual does not tell you

[Mattsson96]

Hello friends.

This is not a cry for help rather than some useful tips I wish the MSI manual would have told me before trying to flash the BIOS using the built in BIOS Flash button.

 

Disclaimer: I have not tried many MSI boards, so this may not apply to all.

 

First and foremost, this is what the manual (MAG B550 Tomahawk) says:

That is all good, and of course they don't lie. But I feel that they leave details out that I would have loved in there. So here are my list of additions:

 

1. Do not use a USB3 stick (I never did it myself but I have heard they won't work). Some people report sticks less than 16GB gives best result, hard to say if this is random or not.
2. Even if you think everything has worked (as it acted like the manual said), be sceptical. The true indicator that the flash was sucessful in our case was that both the USB LED and the BIOS Flash LED blinked for quite a long time (3-5 minutes maybe even more) after which the "computer" turned itself and "rebooted". I use quotations as the only parts really making up the PC at this point may be Mobo + PSU. The "reboot" is indicated by the motherboard fan turning off completely and then spinning up again. Only at this point is it safe to say that the flash was successful and you can turn the PSU off and remove the USB.
3. If you don't achieve the behaviour described in step 2, try again. We tried 3-5 times with the very same stick, making no changes to it whatsoever. On the fifth time it worked and went the whole way through. No need to take the stick out in between runs, but obviously you need to turn the PSU off and on again in between. Changing USB sticks may also help, but I wonder if it has just been the retries that have helped in the end, for the people reporting "swapping the stick helped". If at first you don't succeed, then try and try again.
4. IMPORTANT: If you have a failed flash and try to boot the PC with a CPU+Memory in it, it might not post, even if it is a CPU that should be supported out of the box. We realized this the hard way, we thought we could simply use an older CPU to flash the BIOS "the old fashioned way", but no. It seems like a failed BIOS button flash could leave your motherboard in some kind of "in between state" where there is no real BIOS working on it or something like that (Don't quote me on that, the point is that it would not work with any CPU, supported or not, even after clearing CMOS). We eventually solved this in between state by successfully flashing the BIOS using the method described in step 2-3.
5. It may be good to do this without any components plugged, but I am not sure if it actually matters... I actually don't think it matters, but correct me on this one. We only had PSU + Mobo because "better safe than sorry".
6. When uncertain, clear CMOS using JBAT1. It does not hurt and could save you time if your flash starts working after a simple CMOS reset. 
7. CPU_PWR2 does not need to be plugged (as stated by the manual not mentioning it, but some people don't believe it)

 

Those are the things I wish I knew before we had a go. The board I learnt most of this from was the MSI MAG x570 Tomahawk WIFI, but I know most tomahawks have the same Flash button functionality.

 

If I am forgetting something, or you have something to add to the list, please suggest it below and I will add it!

 

I really hope people come across this and it saves them time in their debugging. It would have saved us more than five hours.

 

Cheers and happy debugging!

 

[Ankh Tech]

18 minutes ago, Mattsson96 said:

Hello friends.

This is not a cry for help rather than some useful tips I wish the MSI manual would have told me before trying to flash the BIOS using the built in BIOS Flash button.

 

Disclaimer: I have not tried many MSI boards, so this may not apply to all.

 

First and foremost, this is what the manual (MAG B550 Tomahawk) says:

That is all good, and of course they don't lie. But I feel that they leave details out that I would have loved in there. So here are my list of additions:

 

1. Don't use a USB3 stick (I never did it myself but I have heard they won't work). Some people report sticks less than 16GB gives best result, hard to say if this is random or not.
2. Even if you think everything has worked (as it acted like the manual said), be sceptical. The true indicator that the flash was sucessful in our case was that both the USB LED and the BIOS Flash LED blinked for quite a long time (3-5 minutes maybe even more) after which the "computer" turned itself and "rebooted". I use quotations as the only parts really making up the PC at this point may be Mobo + PSU. The "reboot" is indicated by the motherboard fan turning off completely and then spinning up again. Only at this point is it safe to say that the flash was successful and you can turn the PSU off and remove the USB.
3. If you don't achieve the behaviour described in step 2, try again. We tried 3-5 times with the very same stick, making no changes to it whatsoever. On the fifth time it worked and went the whole way through. No need to take the stick out in between runs, but obviously you need to turn the PSU off and on again in between. Changing USB sticks may also help, but I wonder if it has just been the retries that have helped in the end, for the people reporting "swapping the stick helped". If at first you don't succeed, then try and try again.
4. IMPORTANT: If you have a failed flash and try to boot the PC with a CPU+Memory in it, it might not post, even if it is a CPU that should be supported out of the box. We realized this the hard way, we thought we could simply use an older CPU to flash the BIOS "the old fashioned way", but no. It seems like a failed BIOS button flash could leave your motherboard in some kind of "in between state" where there is no real BIOS working on it or something like that (Don't quote me on that, the point is that it would not work with any CPU, supported or not, even after clearing CMOS). We eventually solved this in between state by successfully flashing the BIOS using the method described in step 2-3.
5. It may be good to do this without any components plugged, but I am not sure if it actually matters... I actually don't think it matters, but correct me on this one. We only had PSU + Mobo because "better safe than sorry".
6. When uncertain, clear CMOS using JBAT1. It does not hurt and could save you time if your flash starts working after a simple CMOS reset. 
7. CPU_PWR2 does not need to be plugged (as stated by the manual, but some people don't believe it)

 

Those are the things I wish I knew before we had a go. The board I learnt most of this from was the MSI MAG x570 Tomahawk WIFI, but I know most tomahawks have the same Flash button functionality.

 

If I am forgetting something, or you have something to add to the list, please suggest it below and I will add it!

 

I really hope people come across this and it saves them time in their debugging. It would have saved us more than five hours.

 

Cheers and happy debugging!

 

really helpful, planning to get a x570 tomahawk, this could save my life.

[Mattsson96]

10 minutes ago, Ankh Tech said:

really helpful, planning to get a x570 tomahawk, this could save my life.

Hope your build will be as painless as possible  Making sure the BIOS flash actually succeeded really proved the key yesterday in our x570 tomahawk build.

[Ankh Tech]

Just now, Mattsson96 said:

Hope your build will be as painless as possible  Making sure the BIOS flash actually succeeded really proved the key yesterday in our x570 tomahawk build.

maybe by the time I get it the bios for ryzen 5000 will already be on there. But if not, thanks man