MP 1,1-5,1 Fan

[jimbop555]

Hello, I have a Mac Pro 5,1 and i seem to be having a fan speed issue on processor BOOSTB . The fan control App reads 0 and the fan is spinning fast. I'm unable to adjust the fan speed in the fan control app. I tried changing out the heat sink and still no change. CPU BOOSTA fan is spinning a little faster than normal but is adjustable in the fan app. everything runs normal if I swap the CPU tray to a single CPU. SMC version is 1.39f11 the same with the tray. North bridge looks clean and secure. I suspect the Processor board might be defective. Any Ideas? I appreciate.

 

[MacProRestoreGuy]

Were you able to solve this issue? I am having the same problem but with BOOSTA.

 

[tommy chen]

this could be a sign that the heatsink of the CPU is not properly seated and the contact with the fan connector on the CPU tray is faulty.

 

[MacProRestoreGuy]

I'm thinking it's the board. I didn't have it properly grounded when I was working on it. I've upgraded two trays since and no issues. I suppose a work around would be to replace the fan with a switch operated fan. Not sure if I will go that route, though. Machines not being used so not a big deal. I can also crank up the other 3 CPU fans to over compensate. Thoughts?