820-3662 - Fans spin high


New member
I have a 820-3662 that suffered liquid damage. The unit was badly liquid damaged in the eDP connector area, audio and thunderbolt. I removed the damaged components and soldered a new connector. The unit powers on a works fine except the fans always spin at max RPM but only after the OS is booted. (I tried known good OS as well) Ran ASD OS and the unit passes all test. I can't figure out what is causing the fans to ramp up. Any ideas ?


New member
Thanks Louis,
I think this might be it.

type : current
low-limit: 0.0A
high-limit: 0.05A
Description: Debug TBT T29 Current
Reading: 0.804A
Noise-Tolerance: 1.0

The thing is I worked on that area for a while, meticulously replacing components but I only got one of the ports to work. Guess I have to find the culprit and get the other port to work to fix the fan issue.


Current sensor usually does not cause fan issues but lets fix it anyway. It reads way too high so probably corroded trace from pin 4/5 of U5640 to R5640.

Run EFI version of ASD and check sensors.