Chosen Solution
Water spill on my MB Air. Replaced the logic board. Batteries will not charge (a separate issue), so I start it up with the magsafe plug attached. Boots like normal, but by the time it gets to the login page, the FAN IS RUNNING AT MAX. The fan speed gradually increases over the first ~30sec after booting. Any suggestions are greatly appreciated…
Check both sides of the trackpad cable, the trackpad PCB and I/O cable for liquid damage and burnt pins. If any of these have issues or are not recognised it will cause the fan to spin high speed.
Try changing the fan speed in settings.
