Macbook 820-00165 Fan Spins

[Instafixx]

PPBUS
Pp3v42
SMC Reset
PM SLP S4 L

all ok

U1950 Voltages are erratic. I get them but it dies down randomly. Fan Spin also random

 

[Instafixx]

Cleaned and re installed U1950 . Getting all voltages when there is fan spin. Voltages drop to zero when fan stops. (U1950)

 

[Instafixx]

It goes upto 200 mAh then goes down to zero once when the fan stops and then i get max fan spin and Amp Draw is stuck at 240 mAh

 

[2informaticos]

Any history available?
Pin 3/U1950 goes high?

 

[Instafixx]

No History.
Yes Pin 3 goes high when fan is spinning

 

[2informaticos]

What about PLT_RESET_L?

 

[Instafixx]

PLT_RESET_L IS 0V

 

[2informaticos]

What about CPU_VCCST_PWRGD and CPU_VR_READY?
If good, then heat PCH with quality flux.

First be sure, all voltages from page 11 are there.

 

[Instafixx]

U1930 / c1930 / r1931 missing on the board.

Repairs have been done previously. Should we install them first ?

 

[2informaticos]

Of course; PCH requires CPU_VCCST_PWRGD...

 

[Instafixx]

Reconstructed all the Missing Points around U1930.
Now i get PLT_RESET_L at 3.3V.
Pin 3/U1950 stable at 3.4V

CPU_VCCST_PWRGD IS 1V
CPU_VR_READY IS 0V. The fan stops spinning as soon my probe touches R1955 Pin 2.

 

[2informaticos]

CPU_VR_READY is a very sensitive test point.

Do you get USB activity now?

 

[Instafixx]

My usb tester just went bad a couple of days ago. A new one will come in a week. I dont have a usb with led to test. But i get a constant fan spin.

 

[2informaticos]

You can use a bootable pendrive with LED link.

 

[Instafixx]

I have light on the ssd when connecting a external ssd.

 

[2informaticos]

Just steady power LED, or flashing Link LED too?

 

[Instafixx]

Flashing too.

 

[2informaticos]

Try PRAM reset, should bring chime on.
Internal Caps Lock LED should also react.
Check external video too.

 

[Instafixx]

PRAM reset did nothing .

 

[Instafixx]

Is it repairable?