Case Fan Wont Turn Off? After Upgrade.

New Asus B250M-C motherboard
New CPU I5-7500
Windows10

If I physically set computer to sleep mode in the "shut down/sign out" option, it turns off fine. If computer goes to sleep after 30 minutes as set, the case fan keeps running. Forever. The existing fan is 3 wire, the connector on motherboard 4. From research, this should still work fine, as 4th wire is for PWM speed control. Not a serious problem, but its in the bedroom! Small place. Did look for a new fan, but its a 80mm "slimline" and all I could find in 4 wire at Microcenter were much thicker, and not able to fit. [there's a dedicated holder]

 

Task manager says there are no apps running, but 61 background processes, and 85 Windows processes running. If one of these is preventing "sleep" mode, how do I find it?

 

Its most likely a bios issue, check in the bios what the minimum fan speed allowed is and set it to that.....reboot and retest!
Sometimes, when fan speeds are set at higher rates in the bios, it wont turn them off in sleep mode.

 

Solved! Not quite sure how. Changed two things after suggestions from a member at the Marietta Maker Station. Under "advanced power settings/multimedia settings/when sharing media" I selected "allow computer to sleep". At the same time I deleted Google updater. Apparently it runs continuously.