Heatsink fan stops spinning when case is vertical

[Jackal30]

Has anyone seen this before? If the case is in it's normal position (vertical), heatsink fan will stop spinning or barely spin causing the computer to overheat and shut off. If i lay the case horizontally (so the cpu/fan is facing the ceiling), the fan spins perfectly indefinitely and core temperatures are fine.

Obviously i know i can just replace the heatsink/fan but wondering if anyone has seen this before or if there is a fix? Thanks.

 

[MagnusTheBrewer]

Sounds like either a loose connector or, dust build up in the fan.

 

[Burpo]

More like the bearings are shot or gummed up. If cleaning doesn't help, I'd replace the fan.

 

[pcgeek11]

Gummy worn bearings or bushings.

 

[denis280]

wires or dust in contact.or the the fan