MP 6,1 Fan on Mac Pro (Trashcan) running at full speed.

[Ben1l]

Hi all,

The fan on my Mac Pro (Trashcan) Is running at full speed all the time, no matter what it's doing. I've bought a new Mac, but want to sell this one. I've done a complete fresh install of Catalina but that hans't helped. I've taken the fan assembly apart and removed the build up of dust, which helped for about 2 hours, but the fans are now spinning at full speed again.

Any ideas of what I can do to slow them down so I can truthfully sell it as 'full working order'?

Thanks!

 

[vett93]

Have you tried SMC reset?

 

[Ben1l]

Have you tried SMC reset?

Yup. No luck.

 

[Selsk]

Not sure what the actual problem is. I have the same issue with my trashcan. I ran the diagnostics where you hold D on boot. I got 2 errors. Issue with the SMC (PFM006) and issue with the Power Management System (PPN001).

I'm not sure what those are but reseting doesn't help. I just use the Macs fan Control to keep the fans in check. Everything else works as normal.

 

[MisterAndrew]

It's probably some kind of hardware fault. Some people have reported this happening after installing a new CPU. Probably best to take it to an authorized Apple service provider for diagnosis.

 

[Selsk]

It's probably some kind of hardware fault. Some people have reported this happening after installing a new CPU. Probably best to take it to an authorized Apple service provider for diagnosis.

Yes but that sounds very very expensive. I feel like it may have started around the time I changed the thermal paste on the cpu so I might have not tightened something down properly or who knows. I might disassemble it again to have a peek.

 

[IowaLynn]

Bent pin? too much or not enough thermal paste, in which case take a peek. And whether it is a known issue with that processor in "trash can." Exchange or try with a 2nd cpu.

 

[MisterAndrew]

Yes but that sounds very very expensive. I feel like it may have started around the time I changed the thermal paste on the cpu so I might have not tightened something down properly or who knows. I might disassemble it again to have a peek.

This makes sense now. I'm sorry that happened. These machines are delicate. Repairs require special equipment and knowledge. Do you have a copy of Apple's technician guide? It's posted in another thread with "LED diagnostics" in the title or you can buy it from a seller on eBay. I suggest to not follow the directions in any YouTube video or other non-Apple source. Follow Apple's instructions only.

Make sure the exact torque specs are observed. You'll need to get a torque screwdriver if you don't have one. Also pay careful attention to the flex cable routing. It's possible it became kinked or damaged during re-assembly. Apple's instructions include photos of the correct and incorrect routing.

Apple may not charge you that much to fix it. I've heard people have gotten away for about $500 with a logic board or GPU replacement.

 

[h9826790]

Yes but that sounds very very expensive. I feel like it may have started around the time I changed the thermal paste on the cpu so I might have not tightened something down properly or who knows. I might disassemble it again to have a peek.

If there is any Apple store around, take it to have a check, checking is free.

 

[iliyan61]

make sure the CPU is properly tightened down properly but its not a huge deal IMO just use macs fan control rather then wasting 5+ hours and more money on it.