MacBook Air 2018 A1932 820-01521 not charging

[Moosiv]

Hi, I have this MBA which was water damaged, I've cleaned the corrosion and replaced a handful of resistors and both CD3215 twice.

PPBUS_G3H = 12.78V
I've attached all other measurements as per logi.wiki.
Currently stuck at 5v O.24A Not cycling.
I've put my own board in this mac and charged the battery - the mac appears to work absolutely fine other than charging. No device recognised on the USB ports - changed ports - same results.

some ore measurements

I2C SDA & SCL is 1.8V
ppbus_g3h 12.38V
pp3v3_g3h_rtc 3.32V


Can anyone shed any light on what I'm missing please?

[mon2]

Re: MacBook Air 2018 A1932 820-01521 not charging

If the charger is not selecting the 20v power delivery contract then the fault is still with the cd3215 ace controllers.

Remove all power. Meter in diode mode.

Red probe to ground.

Black probe to pin to test.

Check the diode mode readings of CC1 and CC2 lines of each type C connector. These CCx pins are used by the power adapter for the BMC communication.

Be sure the power adapter is the proper one for this logic board. Only if the CCx pins are working will the power delivery contracts be imported from the adapter to the logic board.

[Moosiv]

Re: MacBook Air 2018 A1932 820-01521 not charging

Firstly, thank you for taking the time to help me.

Diode reading from TP as requested.

XA CC1 0.655
XA CC2 0.652

XB CC1 0.651
XB CC2 0.653

[mon2]

Re: MacBook Air 2018 A1932 820-01521 not charging

Diode readings look fine.

Review the voltage to ground of:

(for example for the CD3215 @ U3100 = repeat for each CD315)

PP3V3_UPC_XA_LDO
PP1V8_UPC_XA_LDOA
PP1V8_UPC_XA_LDOD
PP1V1_UPC_XA_LDO_BMC
PP1V8_SLPS2R
PP3V3_G3H_RTC
PHV_INT_XA_G3H
PP5V_G3S

[mgjini]

hello there, i would like to ask also for some help on this sort of issue, i also have a 820-01521-a which battery is not charging it show charging sign but it doesn't charge, the story of this is that someone has tried to replace the battery and i can see that this is not a genuine battery, i have got a genuine battery from another macbook and i am having same issue, i have done some measurements and i have the same as above user for those:

XA CC1 0.655
XA CC2 0.652

XB CC1 0.651
XB CC2 0.653

but with the battery not attached i get 12.46v f7000 fuse, and if i was to attach the battery and power on, some time f7000 give me only 0.168v, i have notice with battery atached

[mon2]

May be a leaky mosfet onboard in the ISL (F7000) region. Review the battery mosfet @ Q7065. Remove all power. Meter in resistance mode.

Measure the resistance across this mosfet as follows:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. If the measurement is low, it could be leaky.

Q: Does the Power section of the OS show the details of the battery? The # of charge cycles, etc. ?

[mgjini]

hi there, first of all many thanks for your always help to the community in here

i am measuring this on diode mode and everytime i get different measurements

on source 1 2 3 some times i get 0.945 mo, some times i get 1.455 mo than if i start and measure again i get:

source 1; 1.650 and goind down mo, source 2: 1.389 mo and going down, source 3: 1.1745 mo and goind down

measuing the drain is a bit tricky as their is capacitors there on the way

drain 5, 6, 7, 8: 2.1 mo and going up

source 1 to gate 4 4.975 and going down
source 2 to gate 4 5.201 and going down
source 3 to gate 4 4.825 and going down

gate 4 to drain 5,6,7,8: 6.0mo and going up

i hope i have done it right

[mon2]

Hi. You are quite welcome. Keeps the mind from rotting.

It will be better if you can measure with your meter in resistance mode. Select a high resistance scale if manually selected on your meter.

then check across the mosfet pins as noted above.

for example, meter probes across source (1-2-3) and drain (5-6-7-8), etc. What is the resistance? Be sure to post the meter scale setting during the tests.

repeat for the other permutations as noted above.

if you see ‘1' then the meter scale is too low. Select a higher scale on the meter to measure.

[mgjini]

hi, so it is not even 1 oms, when i start measuring it is 1.453 than if i keep holding it goes below 0.943 mo, same pin 2 and 3

5,6,7,8 2.579 mo

[mon2]

Hi. No, you are measuring to the ground pad with the red probe in the picture. Meter in resistance mode. One meter probe (either color) to the one mosfet pin; other meter probe to the other mosfet pin. Need the measurements across the same mosfet.

So the permutations we are after here are:

source (1-2-3) & drain (5-6-7-8) ; pick any of the pins in the bracket since they are tied together on the mosfet body
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

If your meter reports a '1' then the resistance is higher than the selected meter scale -> switch to another scale till you have a proper measurement.

[mgjini]

after measuring source 1 2 3 to drain 5 6 7 8 i get 2.5 mo

source 1 2 3 to gate 4 i get 4.6 mo
gate 4 to drain 5 6 7 8 i get 4.8 mo

[mon2]

To confirm, your units of measurements are mega-ohms? Then it should be written as Mohms. As compared to mohms = milli-ohms. Very few techs will have a mill-ohm meter - personally still shopping around for one.

Assuming yes then these measurements are ok for the tested mosfet. This was for Q7065? It is not shorted.

Proceed to test the resistance to ground @ F7000. No power during this test. Need to be sure this part of the rail is not shorted.

The next test can be tricky - still with no power to the board - meter in the lowest resistance scale. Measure the resistance across C7020. What you are doing here is measuring the full path resistance of the current sense resistor. Ideally it should be measured at the charger IC but the very tiny charger IC = ISL9240 does not offer pads to probe so we have to find nearby parts with the same connection.

This full path resistance should be ~2 ohms = R7061 + R7062 + the milli-ohm resistor @ R7060 (your / my meter cannot measure this tiny resistance). Confirm it.

NB: If this full path resistance is not ~2 ohms then the charger IC will detect this fault and shut down the charging of the battery for safety reasons.

[mgjini]

so f7000 fuse, with power connected i have 12.50v but it switches to 0.178v every second on both sides of the fuse, removed power, measuring the c7020 it gives very low reading, 002.3 Ohms (Ω) other readings have been mΩ
r7061 gives 100.9 kΩ, R7602 give low reading also 001.1 Ω both r7602 and c7020 which are near the chip give low readings

all those measurements are by touching with probes both sides of the capacitos

[mon2]

r7061 gives 100.9 kΩ

Can you confirm this measurement again? It should be about 1 ohm (not 100k ohms = 100,000 ohms). You will need to remove all power -> meter in the lowest scale (if manual meter) and then measure across R7061 with the meter probes. Also, do short your meter probes to get a reading of what '0 ohms' should read on your instrument.

c7020 it gives very low reading, 002.3 Ohms (Ω)

This is the correct reading for the full path resistance so R7061 must be a typo on the measurement but do confirm it.

[mgjini]

yes C7020 give 002.5 Ω

[mgjini]

[mon2]

Given that the resistance across C7020 = 2.5Ω, assuming that the measurement of R7061 is in error. Can you confirm that you have each of the meter probes across R7061. This measurement must be ~1Ω. Same for R7062.

[mgjini]

so measuring R7601 even if i swap the probes each side i get 100.6 kΩ, measuring R7602 again swapping either side i get i think much much lower which is 001.1Ω, if i turn my meter to 80Ω and try to measure r7602 it will not give results, if i turn my meter to 800kΩ it would read R7602 and gives this result 100.6 kΩ

[mon2]

Select the 800Ω scale and test each again.

[mgjini]

Select the 800Ω scale and test each again.

r7602 = 001.1Ω

C7020 = 002.5 Ω, r7601 can not read at 800Ω no results at all on meter if i switch it to 800KΩ will read 103.2kΩ