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BeatCrazy

macrumors 603
Original poster
Jul 20, 2011
5,008
4,343
EDIT: fixed it ha. Turns out I inserted my LCD temp sensor connector to the Logic Board upside down. All good now.

Hi all,

I should start by saying I know my way around this iMac pretty well, but I think I caused a self-inflicted wound, and I don't know how to troubleshoot. I took this machine apart to replace a BT module, and now my fan runs 100%.

At first I thought it was a mangled LCD temp sensor cable (that got a stronger-than-expected pull), but that visually seems OK now.

I have reset SMC, PRAM, etc. No change. I know you can run Apple Diagnostics, but my iMac is running Big Sur via OCLP, and holding D while booting doesn't seem to work.

Is there software I can use that will pinpoint which sensor is causing my fan to go 100%?
 
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Nguyen Duc Hieu

macrumors 68030
Jul 5, 2020
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Ho Chi Minh City, Vietnam
EDIT: fixed it ha. Turns out I inserted my LCD temp sensor connector to the Logic Board upside down. All good now.

Hi all,

I should start by saying I know my way around this iMac pretty well, but I think I caused a self-inflicted wound, and I don't know how to troubleshoot. I took this machine apart to replace a BT module, and now my fan runs 100%.

At first I thought it was a mangled LCD temp sensor cable (that got a stronger-than-expected pull), but that visually seems OK now.

I have reset SMC, PRAM, etc. No change. I know you can run Apple Diagnostics, but my iMac is running Big Sur via OCLP, and holding D while booting doesn't seem to work.

Is there software I can use that will pinpoint which sensor is causing my fan to go 100%?

Can you give more info on the BT module? Same as the stock, or upgraded?
 
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