Macbook 820-00165 Cycling

[Instafixx]

Fan Tries to Spin and Stops.

PPBUS is 8.6V
I get magsafe light.

Looks like some work was done Near U8160 . Pads missing from the board. This is a blank spot on the board and not a chip - idk what was the person trying to do.
Lines not shorted.

What can be the issue ?
R1500 and R1380 seemed corroded. Replaced them.

PM_SLP_S4_L is cycling as well.

 

[2informaticos]

Cycling every 5s, or just two times and stop?

Tested in SMC bypass mode?

 

[Instafixx]

every 5s.

Doesnt work in SMC Bypass

 

[2informaticos]

Check related coils and rersistors from page 11.

820-00165 Pulsing - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

 

[Instafixx]

You want DIODE mode readings or Resistance across Pins ?

 

[2informaticos]

I didn't say anything about ground related readings!
Just check continuity between pins for resistors and coils.

 

[Instafixx]

R1270 is 1.5 Ohms
R1275/80 is 1.4 Ohms
L1270/75 is 1.4 Ohms
L1290/95 is 1.4 Ohms

 

[2informaticos]

Did you test all recommended on the logiwiki page?

 

[Instafixx]

CPU_VCCST_PWRGD pulses too.
But the Jtag is clean

 

[Instafixx]

Removed the JTAG.
Reflowed U6100 and adjacent areas as well. Nothing till now.

 

[2informaticos]

Possibly more corroded components.
There may also be accumulated crap under CPU.

 

[Instafixx]

Heated the CPU with flux. Still the same.

 

[2informaticos]

PLT_RESET_L pulsing too?
If not, check at pin 3/U1950 too.