macbook a1286 820-2915-b not turning on

[marcelofct]

friends I need your help I have this macbook a1286 with the motherboard 820-2915-b but I can't fix it when I connect it to the power supply it turns on the green light and consumes 0.01x amp x= I don't have a 4-digit power supply, looking into schematic I do not have PP5V_S3 that comes out of ic u7201 I have the following
PPBUS_G3H=12.59
PP3V42_G3H= 3.48
PPVRTC_G3H=3.48
PP5V_S5=3.34
PP5V_S3=0V

ic u7201
EN = 2.XV
EN1= 0V
EN2=2 3.3V
PGOOD =0V

please help
attached boardview and schematic
apparently boardview does not match

[mon2]

Re: macbook a1286 820-2915-b not turning on

PP5V_S5=3.34

Can you recheck this rail ? It should be 5v0 and is created by U7201 (pin 29).

If it is not 5v0, remove all power -> meter in resistance mode -> check the resistance to ground of the same PP5V_S5 rail.

Post your readings and the scale on the meter used for the measurement.

[marcelofct]

Re: macbook a1286 820-2915-b not turning on

Can you recheck this rail ? It should be 5v0 and is created by U7201 (pin 29).

If it is not 5v0, remove all power -> meter in resistance mode -> check the resistance to ground of the same PP5V_S5 rail.

Post your readings and the scale on the meter used for the measurement.

my bad the real is
PP3V3_S5=3.34
Can you recheck this rail ? It should be 5v0 and is created by U7201 (pin 29).
VREG5 =5.01V (pin29) / diode mode 0.450v with red probe on ground / resistance to ground 180.0k

gracias por la ayuda
greetings

[mon2]

Re: macbook a1286 820-2915-b not turning on

Review this webpage:

https://www.it-tech.com.au/mac-q-a/pm-slp-s4-l-timing/

because EN1= 0V (U7201).

EN1 on U7201 = PM_SLP_S4_L.

This EN1 signal in turn is used to turn on PP5V_S3.

[reformatt]

Re: macbook a1286 820-2915-b not turning on

The 820-3115 board has a numbered power sequence. Basically the same for this board so use that to troubleshoot. If you not getting to PM_SLP_S4 there can be many reasons for it.

[marcelofct]

Re: macbook a1286 820-2915-b not turning on

thank you all , i will try to fixit