Macbook A2337 820-02016

[iFix]

Hi guys.

I have this board with no power stuck at 5v 0.55amps and small fluctuations on the side of the amps. On the thermal camera, U5200 pulses. No short on U5200 and surrounding components, no liquid spill, and no voltages going to the PMU U8100. Would appreciate your help on this. Thanks

 

[2informaticos]

PPBUS_AON voltage?
If no present, remove F5200 and check C5254 voltage.

 

[iFix]

PPBUS_AON is present and goes from 11.9 up to 12.2v. Diode mode reading is 455 on F5200

 

[2informaticos]

What about 3V8_AON?

 

[iFix]

PP3V8_AON_VDDMAIN is 0v. Diode more is 317

 

[2informaticos]

Post U5700 basic voltages: VIN, LDO5, PVCC, ENABLE.

 

[iFix]

U5700:
pin 8 PPBUS_AON - 4v
pin 7 PP5V_AON_P3V8VRLDO - 0v
pin 5 P3V8AON_PVCC - 0v
ENABLE - 0v both sides of R5710

 

[iFix]

R5340 on 2m scale measurement shows .430

 

[2informaticos]

"PPBUS_AON is present and goes from 11.9 up to 12.2v"
4V isn't in that range, no?
"pin 8 PPBUS_AON - 4v"

 

[iFix]

Yes 4v, and it was 11.9 up to 12.2 fluctuating. I'm suspecting U5200 has something to do with it

 

[iFix]

I replaced U5200 and now it's the same range. I will re measure again U5700

 

[iFix]

U5700:
pin 8 PPBUS_AON - 11.8-12.2v going up and down
pin 7 PP5V_AON_P3V8VRLDO - 5v stable
pin 5 P3V8AON_PVCC - 5v stable
ENABLE - 5v both sides of R5710

 

[2informaticos]

Then you must get 3V8_AON.

 

[iFix]

Of course I would need to get

 

[2informaticos]

I mean that U5700 should already deliver 3V8_AON.
It has correct power and enable.
Check all surrounding components.

You may need to change U5700.

 

[iFix]

Yes, I checked the standby sequence and checked all surrounding components all measure fine, searching for a spare U5700 from a board. I will update once I replace it

 

[iFix]

The client couldn't wait for a new chip to arrive they bought a new laptop. Thanks for the help