[820-00281] dead!!!! 5v@0,48

[phantomEVO]

hi to all motherboard is perfect. no shorts around usb-controllers
i've 0V on PP1V1_UPC for each controller. (with cable connected) no shorts on those lines

reProgrammed u2890, still the same

3V3_G3H 0v

on R7020 5v on all 4 pins
TBA_AUX_DET 1.2v
TBA_VDDA 4,8v
TBA_VDDP 4.8v
SMC_RESET_L 0v
BUF_SMC_RESET_L. 0v
on d6902 i've PPBUS_G3H 4,8v, on PPVIN_G3H_P3V3G3H i've 1v

[phantomEVO]

i've resoldered a new u3200 and now i have 1,1 on u3200 but not on u3100. still 5v @0,46

i've recheck all lines of u3200

following this guide

https://logi.wiki/index.php/CD3215_Bootup_Sequence

and all are ok until PM_EN_P3V3_G3H where i found 1,9v

i've also PPVIN_G3H_P3V3G3H with 1v

[mon2]

Flux & replace D6902.

[phantomEVO]

hi mon! thank you for the reply! why you think to replace the diode? could i try to remove the diode and make a jumper just for test?

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance to ground of PPVIN_G3H_P3V3G3H = pin # 3 of D6902. If the resistance is low, there is a short on this rail and it could be from the capacitors C6905 and/or C6906.

This dual diode is required to pass through the higher of the 2 input voltages being fed onto pins #1 and # 2, respectively. Whomever is higher, that voltage should appear on pin # 3 (less the Vf = forward voltage drop of ~0v6).

At this time, your voltage on pin # 3 is ~1v. This is because

a) you have a shorted part in this power path OR
b) this dual diode is defective

From our experience, have seen more defective dual diodes but you can test each case. Only after the Vin to U6903 is high enough, then you will have a stable 3v3 @ R6923. This is a critical power rail to the entire logic board.

You can also validate if the dual diode is defective or not by using the DIODE mode of your meter.

Red meter probe onto pin #1; black meter probe onto pin # 3 - the meter should conduct and offer a voltage reading.
Repeat with red meter probe on pin #2; black still on pin # 3.

Now reverse the meter probes and the diode should block = 'OL' on the meter. Post all measurements.

[phantomEVO]

thank you for all your reply...a lot of things happen...i don't remember all the things i've done...i'm sure i've changed the diode and u7000.

now it works! and boot without problem. but only without the battery. with the battery it goes to 20 but it stuck at 0,036 amp and nothing happen..

[phantomEVO]

i don't know what to think....i've disconnected and reconnected all together and it has booted with battery and has charged the battery to the max (it was at 1% with service alert). as soon as i have disconnected the cable, it has powered off. now it doesn't boot anymore with battery. i've tried with another battery, same thing

with power supply and battery connected i have

PPBUS_G3H is 11.81v

3V3_G3H is 3,41

[mon2]

So much going on and many missed details of information. What are the details of the dual diode?

Disconnect the battery. Is the laptop stable with only the official power adapter?

[phantomEVO]

you are right! i've mounted the same diode. taken from a donor board (a1466)

the macbook boot always from each port with power supply only. and it is super stable. if i connect the battery, it stays at 20v@0.46 amp...

[mon2]

Remove all power. Meter in resistance mode.

Measure the resistance of the battery charge circuit @ C7020. Measure across this capacitor. What is the resistance in ohms? We are checking if there is a break or defect in the current sense loop.

The full path resistance should be ~2 ohms. Confirm this details.

Moving forward...

Q7065 may be defective. Test using the resistance checks across this mosfet.

source / drain
source / gate
gate / drain

If there is a low resistance; this mosfet may be defective.

next..

Connect the battery and adapter.

Measure the voltage to ground of the following points of interest:

R6920 - both sides
R6907 - both sides
PPVIN_G3H_P3V3G3H ; pin # 3 on D6902

SMBUS_SMC_5_G3_SCL ; battery connector
SMBUS_SMC_5_G3_SDA ; battery connector

[phantomEVO]

c7020 3ohm
c7023 2,5ohm

[phantomEVO]

source / drain 35k
source / gate 46k
gate / drain 82k

[mon2]

Flux and remove Q7065 off the board. Allow it to cool down. Then measure this mosfet again while it remains on your work bench. This mosfet is measuring too low to be ok. Each measurement should be hundreds of k ohms or higher if normal.

[phantomEVO]

ok, i've reconnected battery and power supply and it booted again. as soon as i removed the cable, it power off. reconnected thecable-> 0,043 -.-'

in this situation i have:

R6920 PPDCIN_G3H_CHGR_R 8,1v / PPDCIN_G3H_CHGR 3,4v

r6907 PPBUS_G3H 12,4/ PPBUS_G3H_R fluctating between 5 and 7,5

pin 3 of diode fluctuating from 4 to 7...removing the power supply, pin 3 is stable at 7v


about the mosfet: i've measured the same identical mosfet on a donor board and it has the same identical values....i've used the multimeter in resistence mode....

[mon2]

Remove all power. Measure the resistance of R6907 which appears to be defective. Should be ~2 ohms.

[phantomEVO]

it measure 26ohm

[mon2]

26 ohms? Too high. Replace this part and test again.

[phantomEVO]

it0s a nightmare: changed the resistence, now it doesnt boot anymore even with power supply only..

this video is with power supply only

https://www.dropbox.com/scl/fi/5spoe...=z83f4i0s&dl=0

with power supply only i have 12,6v on both sides of the new resistance and PPVIN_G3H_P3V3G3H 20v on pin 3 of the diode

[mon2]

These are good measurements.

Do you have a stable voltage for PP3V3_G3H @ R6923 (check both sides of this resistor)?

Suggest to remove the new resistor you have soldered @ R6907. Power up again with the power adapter. Does the logic board power up ok?

[phantomEVO]

3,42 stable both sides.

it doesn't boot even without the resistor