AMD Motherboards - ASROCK B450M Pro4

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ASROCK B450M Pro4 - Boot Problems

Printed From: ASRock.com
Category: Technical Support
Forum Name: AMD Motherboards
Forum Description: Question about ASRock AMD motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=9750
Printed Date: 08 Aug 2025 at 1:24pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com

Topic: ASROCK B450M Pro4 - Boot Problems

Posted By: hitekcomputing
Subject: ASROCK B450M Pro4 - Boot Problems
Date Posted: 24 Sep 2018 at 2:09am

" rel="nofollow - Hello everyone,

I am in process of building my first Ryzen PC, but I am having a strange issue with what I believe is the mobo (ASRock B450M Pro4).

Here are the specs:

CPU - Ryzen 2600X @ 3.6Ghz (Stock, auto settings)
CPU Cooler - Wraith Spire
Memory - 4x8GB Corsair 32GB DDR4 @ 2133Mhz (CMK16GX4M2A2666C16)
GPU - EVGA GeForce GTX 1070 8GB FTW2 Gaming iCX
Primary Storage - Samsung 970 Evo 500GB M.2-2280 Solid State Drive
PSU - EVGA BQ 600W 80+ Bronze Certified Semi-Modular ATX Power Supply
MOBO - ASRock B450M Pro4 (Running 1.20, latest version at time of post)

The issue occurs during the following steps:

Turn on PC - This works... Boots into Windows 10 just fine, no issues.
Turn off PC - This works... Just FYI - all fans stop, computer is off as far as I know.
Turn on PC (right after turning it off, like 5 seconds later) - Makes it to the ASRock screen, but just sits there. I disabled graphical POST (with AsRock Logo), in attempt to see any messages. Only status code on screen is 'A0'

So far, here's what I tried to fix the 'stalled POST screen':

Reset CMOS with jumper
Reset BIOS to default settings
Put in PSU from my other PC (which is working)
Unplug and reinstall all ram.
Install just 1 DIMM of Ram
Unplug and reinstall GPU
Verify front case headers (power button, light, hdd light, reset switch).

The only remedies to the 'stalled POST screen' after a shutdown are the following:

Unplug PSU (or flip switch on back of PSU)
Press the reset switch on front case when stalled (this causes a reboot, and it works)
Wait 2 minutes after shutting down. Then a boot up works normally.

Does anyone have any advice? Not sure what to do (or try) next... Could it be a bad board? This is my first ASRock board - I normally buy ASUS.

Thanks -

Mark

Replies:

Posted By: kerberos_20
Date Posted: 24 Sep 2018 at 5:56pm

that would be harddrive post code

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http://valid.x86.fr/diq4l4" rel="nofollow">

http://www.userbenchmark.com/UserRun/47132492" rel="nofollow - userbenchmark

Posted By: hitekcomputing
Date Posted: 25 Sep 2018 at 12:14am

" rel="nofollow - Kerberos_20-

I saw that A0 indicates issues with IDE and SATA....

I was hoping there would be be a more detailed message for the code, as I have a hard believing there is a real issue with anything SATA / IDE related.

Also, since I don't have any SATA drives plugged in, why would this code show? The only storage drive installed is a M.2 NVME SSD.

Posted By: kerberos_20
Date Posted: 25 Sep 2018 at 1:35am

" rel="nofollow - if u unplug m.2 drive, will a0 go away?

-------------
http://valid.x86.fr/diq4l4" rel="nofollow">

http://www.userbenchmark.com/UserRun/47132492" rel="nofollow - userbenchmark

Posted By: hitekcomputing
Date Posted: 28 Sep 2018 at 3:14am

After contacting ASRock support, they had a few other recommended troubleshooting steps.

The primary recommendation was to remove the board from the case, and to only attach the CPU/CPU Cooler, 1 RAM module, GPU, and boot device.

The result of this test was the same as with the board fully connected in the case - it still wouldn't boot after a shutdown.

I ended up replacing the board, and everything functioned normally.

Thanks for the helpful ideas!

Posted By: xhue
Date Posted: 28 Sep 2018 at 3:40am

By Odin! I swear ASRock's A/AB series must be the most RMA'd ones ever... Big smile

P.S. I'm glad that all is OK for OP now. Hug

Posted By: JaysonJR
Date Posted: 16 Oct 2018 at 1:08am

Same problem here , i can't boot after shutdown pc , already update to the lasted bios , still same issue ...

Posted By: scitch
Date Posted: 21 Oct 2018 at 8:52pm

I had a similar issue with my B450M Pro4.

However disabling fast boot in Windows itself and updating to the newest BIOS seems to have fixed it.

It seems that the manual XMP Settings in the BIOS couldn't be loaded after shutting down the system because of Windows fast boot which prevents certain parts of the system to completely shut down after it has been turned off.

Which actually brought my RAM down to 2100MHz instead of the normal 3000MHz.

Now after disabling Windows fast boot in the energy settings in Windows and updating to the newest BIOS seems to have fixed the issue for me.

Posted By: thomasp423
Date Posted: 23 Oct 2018 at 9:49am

" rel="nofollow - How did you find the B450m pro4 bios update download? I don't see it on Asrock's site.

Posted By: scitch
Date Posted: 23 Oct 2018 at 5:25pm

Go to http://https://www.asrock.com/mb/AMD/B450M%20Pro4/index.asp#BIOS" rel="nofollow - the product page , click on support and then on BIOS.

Posted By: uda-h
Date Posted: 01 Jun 2019 at 7:03pm

Hello all,

that problem is related to more than one modern mobo.
The cause is your OLD PSU which has only 2.5A 5Vsb.

Todays PSUs has 3A 5Vsb minimum.

I spent quite some time discovering this issue.
Something like 5 days :-)

-------------
uda-h

Posted By: xhue
Date Posted: 01 Jun 2019 at 8:20pm

uda-h wrote:

Hello all,

that problem is related to more than one modern mobo.
The cause is your OLD PSU which has only 2.5A 5Vsb.

Todays PSUs has 3A 5Vsb minimum.

I spent quite some time discovering this issue.
Something like 5 days :-)

How much power consumption do you have on the 5V rail?

Posted By: wga22
Date Posted: 27 Feb 2020 at 6:29am

I experienced a "new" issue, for me. The standoffs from the prior ATX board were sitting directly under the solder points for the memory. Reboot loop. Don't ask me how long it took me to work that out. Debugging had taken me to the conclusion that the board was warped since it didn't boot when I put in the screws in the upper left side of board.

Posted By: wga22
Date Posted: 27 Feb 2020 at 6:32am