Question No POST and other issues?
Question No POST and other issues?
CPU Ryzen 9 5900X with 12 cores
MB MSi B550 Mag Tomahawk AM4
Patriot Viper 3600 RGB 2x16 kits x2 = 64GB total
Cooler Gamemax AIO 240mm rad 2 fans
Lexnar NQ790 2TB Gen4
PSU Gamemax 850W RGB fully modular
Case Cooler Master 540 RGB
GPU Evga 750Ti for testing, XFX RX6800 16GB when active
The Issue
It starts up unexpectedly, especially when it seems to do so.
I installed everything and accessed the BIOS.
Checked version E7C91AMS_ABO (31 Aug 2022) and E791AMS_AEO (10 July 2023).
I decided to update to the latest version, clicked M.Fash, rebooted, and confirmed.
It shut down but didn’t power back on—black screen, no fans, LEDs not working.
After resetting the BIOS, removing the battery and PSU, it randomly powered up after a few presses of the PB button at varying intervals.
Once in BIOS, I changed settings: AMP Profile 1 (3600), F10 saved, refreshed RAM, and it restarted at 3600.
But it didn’t fully shut down; fans continued running and LEDs displayed.
Now here’s the problem:
If I disconnect it from the BIOS while holding the PB, it powers up immediately.
I tried changing a few configurations—X AMP Profile 1 (3600), base speed 2880, F10 saved.
After refreshing the RAM, it restarted at 3600, but didn’t completely shut down.
It kept running and LEDs worked.
When I power it off from the BIOS while holding the PB, it remains completely dead.
I verified the pin connection to MB ground is correct, and the voltage check passed.
The issue seems to be with the motherboard itself.
I suspect a power fault or failure in the power delivery system.
I’ve bridged the pins on the MB PW and removed all components except the CPU.
The PSU reconnected and worked in another system.
Leaving the battery and PSU out for a while showed no pattern, but after some time it would power up and display all components correctly—except for an unknown area (A1).
However, readings indicated 16GB A2 Patriot and 64GB B2 total.
My conclusion is that the motherboard is faulty, preventing proper power-on functionality, possibly due to a power issue or failure to discharge.
Apologies, it’s a bit long, but I’ve checked most components. Any advice would be appreciated before proceeding with an RMA. I also have photos of the BIOS.
Welcome to the forums, newcomer!
Your motherboard features a Flash BIOS button located on the rear I/O panel. Apply this feature together with the instructions in your motherboard manual:
https://download.msi.com/archive/mnu_exe...MAHAWK.pdf
page: 33
Proceed with updating the BIOS using the Flash BIOS button.
After completion, reset the CMOS by unplugging from power and the display, then removing the battery for about thirty minutes. Attempt to restart the system by connecting the +ve and -ve pins on the motherboard. Once everything is verified with hardware, try using the power button.
Yes, a faulty BIOS can also lead to similar issues.
MB MSi B550 Mag Tomahawk AM4
I installed everything, submitted the post, and accessed the Bios. The current version is E7C91AMS_ABO (31 08 2022) and the latest is E791AMS_AEO (7 10 2023).
MSI MAG B550 TOMAHAWK AMD AM4 DDR4 CF M.2 USB 3.2 Gen 2 HDMI ATX Gaming Motherboard
Powered by AMD Ryzen AM4 processors, this board draws inspiration from military armor design and is optimized for enhanced performance through Core boost, DDR4 Boost, and Lightning M.2 with M.2 Shielding.
www.msi.com
The most recent BIOS version is 7C91vAF
Hello
Regardless of the bios version, it's a power-up issue—tap "M flash" and "reboot yes," but it won't power back up!