820-01949 - A2337 - Quick Fan Spin for a Few Seconds. Charging and Main Rails OK

[willis6732]

Hello,

This macbook wont turn on. Only a quick fan spin. Sometimes fans spin a few second. Somtimes they spin fast for a few seconds. Other than that no signs of life

All the Coils on the board have voltage and battery charges fine as well.

I noticed this not sure if it is suspicious:
PPVCC_CPU_PH1 / CPUCORE_SW1 = 40 Ohms (Flex Bv shows 90 Ohms)
=.023 Diode Mode (Flex BV shows .090)

I would appreciate som support in the diagnosis.

Th anks,
K

[mon2]

Grab a USB Type C meter and use it to monitor the voltage and current draw from the power adapter and this target laptop.

Measure both and share the measurements.

[willis6732]

Grab a USB Type C meter and use it to monitor the voltage and current draw from the power adapter and this target laptop.

Measure both and share the measurements.

Thanks for the Reply.


Charging threw USB seems fine. The USB power initiates a quick fan spin.

I get 20V on all the ports and It was charging fine at about 1.5a or so, maybe 2 amps. Pretty sure the batt is fully charged now.

So now the USB sits and fluctuates between 40 and 100ma. And then about once a minuite it does a quick fan spin and USB power goes up to around 400ma for a sec.



There Is some Heat coming from the CPU once and a while. I was Wondering if it could be a shorted CPU but thats a total guess...