A2289 Board 820-01987-A Dead?

[Kudeta]

Hello everyone, I think I am the worst repair guy here is my story...

I am trying to repair my daughter's board bought 3 months ago she dropped the macbook pro Board 820-01987 Resulting in no Backlight no Image.

I had fan spin and normal voltage and Amps at this point with the board out.

I tried to take some measurement on the display cable.

Unfortunately I felt a quick hot sensation when I did this... I know I know...

This is where I am at:

When I plug in the A2289 I Get 20.4V and takes 0.13A jumping after to 0.36 sometimes 0.42 and go back down to
0.29A Stays Steady for 10 seconds and the dies to 0.0A
Comes back up to 0.16A and then back down to 0.00A and stays there.

The only schematics and boardview I have found is the 820-01598 Which seems to be close enough to the 820-01987

So keep in mind that these can possibly be wrong but I tried my best to be close to the truth.

Here are some measurements...


PBUS G3H 12.62V
PBUS G3H_SSDO 12.62V
PP3V3_G3H_RTC 3.31V
PP3V3_G3H 3.3V



PP1V8_SLPS2R 1.8V
SIG OUT / PMU_CLK32K_SOC 0.85V
PP1V8_AWAKE 1.8V
PP1V8_SLPS2R_PMUGPIO 1.8V
PP1V1_SLPS2R 1.1V
PP0V8_SLPS2R 0.79V
PP0V82_SLPDDR 0.77V
PP3V3_AWAKE 3.3V
PPVDDCPUSRAM_AWAKE 0.8V
PP0V9_SLPDDR 0.9V
PP1V1_SLPDDR 1.1V
PP1V2_AWAKE 1.2V
PPVDDCPU_AWAKE 0.53V


PP3V_G3H_RTC 3.01V
PP5V_G3S 5.12V (ON C3111)
PP3V3_G3S 3.31V
PP1V8_G3S 1.8V
P5VG3S_PGOOD 1.25V

PPVCCQ_ANI_SSD0 1.8V
PP0V9_SSD0 0.89V
PP2V5_NAND_SSD0 2.52V

PMU_ONOFF_L 1.78V
PP3V3_S5 3.3 V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 2.40V WITH 0 AMPS TAKEN
PP1V8_S5 1.80V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.2V WITH 0 AMPS TAKEN
PPVPCORE_S5 1.04V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN
PP1V_PRIM 1.04V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN

PP1V8_S3 ?
PP1V2_S3 1.2V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN
PP1V_S3 1.04V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN



PP1V2_S0SW 1.2V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN THIS TIME BOARD WENT UP TO 0.50AMP WITH PROBE ON IT
PP1V_S0SW 1.04V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN
PPVCCIO 0.98V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN
PPVCC_S0_CPU 0.03V AT 0.29 AMPS TAKEN AT STARTUP THEN DROPS TO 0.0V WITH 0 AMPS TAKEN Resistance 2.5ohms to Ground Diode 0.005
PPVCCSA_S0_CPU 0.00V
PPVCCGT_S0_CPU 0.00V

U7210 Appears to have all in lines...but



L7210 0.00v pin 1 and 2

L7220 0.00v pin 1 and 2

L7270 0.00v pin 1 and 2

L7410 0.00v pin 1 and 2

L7420 0.00v pin 1 and 2

Rip CPU ?

Thank you for your kind responses and help I am lost at this point.

[piernov]

Re: A2289 Board 820-01987-A Dead?

I assume Apple refused to take it under warranty?

Voltage on CPU_VR_EN_R?
Exact resistance to ground on PPVCC_S0_CPU, PPVCCSA_S0_CPU and PPVCCGT_S0_CPU?

[Kudeta]

Re: A2289 Board 820-01987-A Dead?

I assume Apple refused to take it under warranty?

Voltage on CPU_VR_EN_R?
Exact resistance to ground on PPVCC_S0_CPU, PPVCCSA_S0_CPU and PPVCCGT_S0_CPU?

Thank you piernov for your kind reply.

You assume right! the macbook showed that it fell on the case....

These are the results to your question


CPU_VR_EN_R 1.8V at 0.29 Amps taken for 10 seconds then 0V

PPVCC_S0_CPU 2.4 Ohms

PPVCCSA_S0_CPU 10.0 Ohms

PPVCCGT_S0_CPU 2.4 Ohms

[piernov]

Re: A2289 Board 820-01987-A Dead?

I don't have enough experience on these boards to know what could cause VCCSA not to come up after CPU_VR_EN_R comes up.
Could be an issue with U7100, U7270 or a component around them or the CPU maybe.

Check voltage on VIN, VCC of U7100 and VCIN, VDRV of U7270 at least.

[Kudeta]

Re: A2289 Board 820-01987-A Dead?

Piernov thanks again for taking the time here is what I found:

U7100

Pin 41 Vin 12.62V constant
Pin 42 VCC 5.12V Constant

U7270 This one is tough 820-1987 and 820-01598 dont look the same I found U7270 but caps and Res are not populated in the same way on both boards...

PPBUS_HS_CPU 12.62V

On caps and resistors around the chip I found 5.11V, 4.8V and 12.62V (1 Cap)

VCIN not sure
VDRV not sure

[Kudeta]

Re: A2289 Board 820-01987-A Dead?

I might add
PPVCCSA_S0_CPU is 1V when The Mbp is taking 0.30Amps for 10sec then goes back to 0V

[piernov]

Re: A2289 Board 820-01987-A Dead?

I assumed it was always 0V since for the other power rails you listed 2 measurements.
So issue is on PPVCC_S0_CPU instead, but it's handled by the same controller, but the VRM chips are U7210 and U7220 instead.

[dbteckos]

Re: A2289 Board 820-01987-A Dead?

Hi,

I have same Logic Board to repair (820-01987-06) and have 20V with 48mA which stays stable to this value. I can feel CPU warming but I have no image on the LCD and not on external display anymore. The LCD is ok, I have tested it with a working board.

I have noticied if the TrackPad is not connected, there is a current consumption (max 0,62mA) and drops to 0 after few seconds. That's why I'm asking me if this board needs the to communicate with TrackPad to be able to boot.

I retrieve similar resistance values than Kudeta:
PPVCC_S0_CPU : about 2Ω
PPVCCSA_S0_CPU : 9,8Ω
PPVCCGT_S0_CPU : about 2Ω

and I can measure:
PPVCC_S0_CPU : 0,81V (stable)
PPVCCSA_S0_CPU : 1,02V
PPVCCGT_S0_CPU : 0V

Thanks for your help

[Byeelec]

Re: A2289 Board 820-01987-A Dead?

Really?? You'll look for backlight fuse and driver

[Byeelec]

Re: A2289 Board 820-01987-A Dead?

BTW, Apple also uses an LCD driver. You must know which because there is a USB-C thunderbolt driver

[piernov]

Re: A2289 Board 820-01987-A Dead?

There's no point in troubleshooting backlight circuit if there's no image or the machine does not even complete POST…

[momoomar]

Re: A2289 Board 820-01987-A Dead?

Hey dbteckos did you managed to solve it? i have almost the same issue cuz of water damage..mine is using 20V and 500mA with the TrackPad and 20V with 60mA without it. the fan spins, CPU is warm but no image on the LCD. The U7420(FDMF5804,SIC621) is blown will that effect the image?

[dbteckos]

Re: A2289 Board 820-01987-A Dead?

Hi momoomar, unfortunately not. I left it out for now waiting a real boardview.. But maybe you can help me.
Could you please tell me what voltage you get on the testpoint (beside J8401) with the red arrow on the photo and also diode value when board is disconnected from power ?

Thanks

PS: If U7420 is blown you should try to replace it

[joutrade]

Re: A2289 Board 820-01987-A Dead?

do you have ( PP5V_G3S_CPUREG_MISC ) on ( L8504 ) pin 2 ?

[piernov]

Re: A2289 Board 820-01987-A Dead?

With shorted U7420, very high chance of dead CPU.

[dbteckos]

Re: A2289 Board 820-01987-A Dead?

Yes joutrade 5,12V present on L8504 (pin 1 and pin 2)

[Stephen]

Re: A2289 Board 820-01987-A Dead?

Question do you by any chance have an ultra sonic cleaner like a crest? Possibly would be considered to put it through a cleaner if it’s recently water damaged? I had a board like this, threw it in the cleaner and it booted. Major water damage, worked like a charm after. Sometimes you get lucky with these boards if you clean them up properly. If it doesn’t boot, it also helps you solve the problem faster.

[dbteckos]

Re: A2289 Board 820-01987-A Dead?

I have an ultrasonic cleaner, I will try. What temperature and time settings do you recommend ?

[dokctor]

Re: A2289 Board 820-01987-A Dead?

Hello, did you manage to get it refurbished?

[dbteckos]

Re: A2289 Board 820-01987-A Dead?

Hi, same issue with ultrasonic cleaning