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HP Desktop PC start up: 512-Rear Chassis fan not detected

HP Recommended
HP ENVY Phoenix Desktop - 860-017ng
Microsoft Windows 10 (64-bit)

I fried my original motherboard and replaced the original with an original HP Thimphu Intel Z170.


Since then I get this Start up message 512-Rear Chassis fan not detected and need to press F1 to move on. A bit daunting.


Can anyone help?


I don´t want to cheat the desktop with fake power cords, or even connect an additional fan, which I saw as solutions while researching.


Replacing the so-called FeatureBytes or Build ID?


Why is this so complicated with HP? Even bought an original motherboard. Hmpff....


My original desktop:


The new/same motherboard appears to origin from:
System ID Board: 2B4B (same)

Born on date: 10/11/2016


Newest available BIOS from Feb 12, 2018 installed:
HP Consumer Desktop PC BIOS Update (ROM Family SSID 2B4B) - A0.59 Rev.A (SP85454.exe)

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Message 2 of 2
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HP Recommended


Welcome back to the forum.

I am not a HP employee.


The problem could be a motherboard sensor or the fan may need to be replaced.


Try resetting the BIOS to defaults. Or remove the CR2032 MB battery to reset CMOS. Let the PC sit for about 20 minutes.


Try a new PWM fan if your MB's rear chassis fan header is a four pin header.



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