AB350 Gaming ITX CHA_FAN1 not working
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=113500
Printed Date: 28 Apr 2026 at 7:41pm
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: AB350 Gaming ITX CHA_FAN1 not working
Posted By: Granola6614
Subject: AB350 Gaming ITX CHA_FAN1 not working
Date Posted: 28 Apr 2026 at 4:13pm
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Hello, I have an ASRock AB350 Gaming ITX motherboard with a Ryzen 5 2600. It was running fine under UEFI version 6.20 but that was quite old and vulnerable to a number of attacks so I decided to update it. I first updated it to the bridge BIOS version 7.00, and then to the latest version 10.50 (dated April 8th 2026). The update went well but since then the CHA_FAN1 header on my motherboard stopped working. The fan connected to it works properly if I connect it to the two other fan headers of the motherboard. I really need all 3 fan headers on my motherboard to work because I want individual parameters for the CPU radiator fans, the water pump PWM and the rear exhaust case fan (connected to CHA_FAN1). My rear exhaust case fan is a BeQuiet Silent Wings 3 PWM 120mm. I made sure it responds well to PWM on the CPU_FAN header (accelerating, decelerating, steady speed etc). I have read some people experienced similar problems with other ASRock motherboards after BIOS updates and solved their issue by disabling USB Power On, but this did not solve the issue on my motherboard. I also tried loading system defaults --> no improvement I also tried clearing CMOS --> no improvement I then tried to roll back to BIOS version 10.43 Beta --> no improvement. I cannot roll back to version 6.20 since it is too old for a roll back (if I understand correctly). I also want to mention that this malfunction is independent of the OS. I see this behevior even before OS startup and when navigating the BIOS : the rear exhaust fan is stopped. I have taken a couple of screenshots in the BIOS. CHA_FAN1 speed is reported as "N/A". Could someone please help me solve this issue? Thank you in advance. |
Replies:
Posted By: Xaltar
Date Posted: 28 Apr 2026 at 4:48pm
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Have you checked in your UEFI under hardware monitor-> FanTuning and made sure "Chassis Fan 1 Control Mode" is set to PWM? If that fails then you can try https://forum.asrock.com/forum_posts.asp?TID=630&title=how-to-clear-cmos-via-battery-removal" rel="nofollow - this and see if that gets it working. Let me know how it goes. ------------- 
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Posted By: Granola6614
Date Posted: 28 Apr 2026 at 5:02pm
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Hello and thank you for your reply. I have tried to clear CMOS as you suggested but this did not change a thing : the CHA_FAN1 header is still unresponsive. |
Posted By: Granola6614
Date Posted: 28 Apr 2026 at 5:03pm
| Oh and as I mentioned in my OP, I have made sure to set the control mode for CHA_FAN1 to PWM. |
Posted By: Granola6614
Date Posted: 28 Apr 2026 at 5:21pm
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I have noticed that CHA_FAN1 is not even reported in HWInfo64, which makes me think this is a software/UEFI error. Here are the screenshots : When I was running v10.50 : https://imgur.com/v1YjNuO" rel="nofollow - https://imgur.com/v1YjNuO You can see "N/A" in front of CHA_FAN1 : https://imgur.com/5kHrue1" rel="nofollow - https://imgur.com/5kHrue1 And here is the screenshot of HWInfo64 with CHA_FAN1 missing : https://imgur.com/hh6iQtj" rel="nofollow - https://imgur.com/hh6iQtj (Sorry for the 3 replies in a row, this forum lacks the "edit message" function) |
Posted By: wino
Date Posted: 28 Apr 2026 at 6:18pm
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If you have a water pump you should connect it to CHA_FAN1 and change CHA_FAN1 to W_PUMP mode in the BIOS and the rear exhaust case fan to CHA_FAN2. ------------- AB350 Gaming-ITX/ac 10.50 BIOS | Ryzen 5 5600 | G.Skill Flare X 2x8GB @ 3466 14-14-14-28 1.4 V | Zotac RTX 5060 SOLO | Kingston KC3000 1 TB M.2 | SilentiumPC Supremo M2 550W | Thermaltake Core V1 |
Posted By: Granola6614
Date Posted: 28 Apr 2026 at 7:24pm
Hi, and thank you for your reply. However, I do not believe this is a solution. The CHA_FAN1 header does not work at all since the UEFI update, be it for a fan or for a water pump. What's more the "W_PUMP" mode is really useless IMHO since it runs the pump at full speed all the time, and my D5 PWM pump is much louder at full speed than at lower speeds (and my system really doesn't need a LOT of flow to stay cool). So I really need all 3 headers working in "fan" mode, none in "W_PUMP Mode". |
wino wrote: