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B250-M MXM STX won't POST

Printed From: ASRock.com
Category: Technical Support
Forum Name: Intel Motherboards
Forum Description: Question about ASRock Intel Motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=7085
Printed Date: 12 Nov 2025 at 11:16pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com


Topic: B250-M MXM STX won't POST
Posted By: humand
Subject: B250-M MXM STX won't POST
Date Posted: 28 Dec 2017 at 10:04am
Hi Folks,

I'm hoping to find a way to get my system up and running again after it powered off on its own when I 
toggled a switch of a USB connected game controller (from keyboard to controller mode).

Attempting to restart the system, the power LED flickers on but turns off immediately and remains off, the fans (CPU and GPU) appear to be spinning a little slower than normal, and there is nothing on the screen. 

I have checked the power adapter (I measured 18V so appears OK), i removed all USB controllers (game controller, mouse, keyboard), also removed one memory bank at a time and put it back, removed the battery and put it back, but still the problem persists. 

If I wait about a minute in that comatose state, the fans appears to want to stop but start again right after as if it's trying to restart again on its own - but I'm not sure exactly what it's doing as there is nothing on the screen as it doesn't POST (also both power and HDD LEDs are off, after the initial flicker of the power LED when turned on.

I have wrote to support (no response yet) but I'm hoping I can get some helpful info here as well as I really want to get my system up and running soon.

TIA



Replies:
Posted By: parsec
Date Posted: 28 Dec 2017 at 12:14pm
" rel="nofollow -
Originally posted by humand humand wrote:

Hi Folks,

I'm hoping to find a way to get my system up and running again after it powered off on its own when I 
toggled a switch of a USB connected game controller (from keyboard to controller mode).

Attempting to restart the system, the power LED flickers on but turns off immediately and remains off, the fans (CPU and GPU) appear to be spinning a little slower than normal, and there is nothing on the screen. 

I have checked the power adapter (I measured 18V so appears OK), i removed all USB controllers (game controller, mouse, keyboard), also removed one memory bank at a time and put it back, removed the battery and put it back, but still the problem persists. 

If I wait about a minute in that comatose state, the fans appears to want to stop but start again right after as if it's trying to restart again on its own - but I'm not sure exactly what it's doing as there is nothing on the screen as it doesn't POST (also both power and HDD LEDs are off, after the initial flicker of the power LED when turned on.

I have wrote to support (no response yet) but I'm hoping I can get some helpful info here as well as I really want to get my system up and running soon.

TIA


First, is this the board you are using:

http://www.asrock.com/ipc/overview.asp?Model=H110-STX%20MXM#Specification

What are you using for the power supply? The specs indicate a 19V/220W PSU.

Given your description of what happened after you toggled the switch on the USB connected game controller, something went wrong, and something seems to be damaged. That is either the mother board, the PSU, or possibly both.

If the power LED simply flickers and then shuts off, and the CPU and GPU cooler fans run at a lower speed, something is definitely wrong.

Either the PSU is damaged and not providing the correct voltage or power to the board, or the voltage regulators on the board that convert the 19V input voltage to the usual +12V, +5V, and possibly +3.3V rails used by PC mother boards was damaged on one or more of the rails.

That both the board's power LED and the HDD LED are not on at all after the initial flicker indicates either the board is not receiving the appropriate power, or the voltage regulators on the board are not working correctly. Just measuring the PSU voltage with no load on the PSU does not verify that the PSU is working correctly. A no load voltage measurement should be at least 19V.

I'm curious about the power requirements of the USB game controller you are using. Switching it to controller mode with the PC running seems to have caused the apparent damage you now have.

If you removed all the USB devices powered by the board and it still will not start, and removed the battery, along with the other symptoms, it seems to me either the PSU, the board, or both were damaged.

The only next step is to try the board with another PSU. If it works with the other PSU, then you know your PSU failed. If the board fails to operate with a different PSU, then the board was damaged. Hopefully the CPU and memory were not damaged.




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Posted By: humand
Date Posted: 28 Dec 2017 at 1:28pm
" rel="nofollow - Thank you so much for replying and for the info provided!

The motherboard is almost identical to the one from the link you posted, except that is the B250 chipset as opposed to the Z270.
I purchased it as a barebone system from Newegg, and I am using the PSU that came with it - this is the product link:
https://www.newegg.com/Product/Product.aspx?Item=N82E16856158059
Game controller is:
https://world.splitfish.com/fragfx-game-controllers/fragfx-fragchuck-pc-mac.html

I was able to measure 18.4V on the motherboard directly on the PSU socket.
I was also able to measure 5V on the USB header.
I was also able to measure the 12V on the RGB LED header, as well as on the CPU FAN header.

I assumed I can measure 3.3V on the front panel power LED header, however since the LED does not stay on (it you blink you miss it) I am not able to measure 3.3V there. Is there an alternative location to measure 3.3V to see if that's OK?

Also, do I also need to check for 1.35V or something like that for the memory?

I can try to purchase another PSU from ebay but if I can find the 12V and the 5V I suspect it's not the PSU. I'm curious to find out how the 3.3V (and possibly the 1.35V) check out, now I just need to know where to measure them.

TIA




Posted By: humand
Date Posted: 21 Feb 2018 at 2:13am
For anyone curious,
It turned out that the CPU was the the problem. Once replaced, the system came back to life.




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