MP 1,1-5,1 cMP 4,1 Heatsink Sensor Issue

[00chopperdave00]

Good afternoon friends, I need some advice from the hive mind.

I have a 4.1 dual tray with a sensor problem. The tray passes the hardware test and the cMP chimes and starts as normal. However the intake, exhaust, BoostA and BoostB fans blow at full speed. It's definitely a 4,1 tray and not a 5,1 tray. I've checked the SMC Version and it's 1.39f5. I’ve noticed in Mac Fans Control that there are no sensor readings for CPU A or DIMM 1,2,3 and 4. This is what I’ve tried and I still have the same issue.

• Reseated and repasted CPU A & CPU B
• Reseated, repasted and changed the screws on the Northbridge
• Replaced the CPU A heatsink
• Reseted the PRAM
• Reseted the SMC
• Tested the PSU in another machine and is fully operational

I’d be very grateful for any advice or suggestions!

Cheers!

D

 

[tsialex]

If you do not have any sensors related to the CPU A and the DIMMs for the CPU A , this is a defective SMC and not something simple like a broken tab fan/sensor connector.

Test another early-2009 dual CPU tray with this Mac, test this defective CPU tray with another early-2009 Mac Pro, doing it you will confirm that the problem is located on the CPU tray.

 

[00chopperdave00]

If you do not have any sensors related to the CPU A and the DIMMs for the CPU A , this is a defective SMC and not something simple like a broken tab fan/sensor connector.

Test another early-2009 dual CPU tray with this Mac, test this defective CPU tray with another early-2009 Mac Pro, doing it you will confirm that the problem is located on the CPU tray.

Thanks for that.

I've tried a single tray in the cMP and there's no issue. I've also tried the dual tray in another machine the fans are blowing full so still the same issue. It's definitely something with the CPU tray.

Is there anything that can be done with the SMC apart from a reset?

Cheers,

D

 

[tsialex]

Is there anything that can be done with the SMC apart from a reset?

As a user, maybe trying to clean the CPU tray, but nothing else.

As a technician, you can trace the circuit and try to find what is damaged, but this will be probably more expensive when you account replacement parts/supplies/time/equipment depreciation than getting a dual CPU tray PCB replacement, $175 last time I've checked. You will probably have to get another dead CPU tray to make one working.

661-4998 Apple Processor Board 8-Core (without processors) for Mac Pro Early 2009 820-2336-A

661-4998 Apple Processor Board 8-Core (without processors) for Mac Pro Early 2009 820-2336-A Where Used : Mac Pro (Early 2009) Apple Model #: 661-4998 , 6614998 , 630-9402 , 820-2336-A Product EEE Code (Refer to general questions): 1LU , BXZ ,

www.dvwarehouse.com

Btw, if you search carefully you probably can get a whole dual CPU early-2009 Mac Pro for the $175.

 

[00chopperdave00]

That's great, thanks for the advice.

As a user, I just wanted to make sure I'd exhausted all repair options. It's a spare tray so no loss.

Thanks again,

D