MacBook Pro 14" M1 Pro Issue (Works but issues)

[Stephen]

Were you able to run diagnostics? Fearing a thermal sensor has gone AWOL

Sadly no, it won't even let me run Diagnostics it just shuts off and turns on. Got a good donor board here so hoping to solve this so we can get this nice computer up and running fully.

[Stephen]

I know this has to be something easy to fix if we knew where to look. No bites?

[Stephen]

Cannot run Diagnostics it crashes. Still sitting on this in our shop. Something we own, board is perfect looking. Did replace ISL9240 and still has the same issue even with new chip so that rules that out. Thermal sensor? You think that is something I can pin point not he board and replace. I have a few donor boards on hand.

[Stephen]

Hello, now coming back to this computer. Still boots and runs fine for one minute then crashes and repeats once it warms up. Any idea where I can look on the board to fix this issue? Would like to know where to start for this. Easy fix I believe but would love to know where to start. Thanks again.

[kevingill]

Can you access the System Logs? Just hoping something was written to indicate what happened?

[Stephen]

Can you access the System Logs? Just hoping something was written to indicate what happened?

Cannot access them since it crashes immediately.

[kevingill]

I'm assuming (probably like you) that it's a thermal or voltage sensor that is reporting over a limit.
I can only think you check each one when it powers up and see if any are looking a bit odd.

[mon2]

1) Can you DFU this unit?

2) Review each and every I2C line on the board. Check their voltage to ground and compare against the schematic expected voltage levels. If an I2C line (SCL and/or SDA) is stuck, then the I2C slaves (mostly sensors) will appear to be defective. The reboot power cycling may be from a timeout of the I2C slave nodes.