Macbook Pro M1 820-02020 - no display

[piernov]

according to schematics RP844 and RP845 should be 0ohm ?

.

[obelix24]

mon2
BL_PWR_EN - 0V
I2C_BKLT_SCL - 5,2V
I2C_BKLT_SCL - 5,2V

[mon2]

Voltage of IPD_LID_OPEN_1V8 ?

[obelix24]

IPD_LID_OPEN_1V8 - on trackpad connector (pin 1) - 1,8V

I found that there was missing one cap C5824 I've replaced it but behaving still the same

[obelix24]

mon2 any idea ?

[mon2]

Does the trackpad function when using the external hdmi display?

[obelix24]

mon2 I'm not able to get output to external display (as the touch bar is not showing anything) but external display recognizes macbook and on macbook screen i can operate mouse.

[mon2]

Are you using a USB mouse or the trackpad? It is important.

Have you attempted a DFU?

https://iboysoft.com/wiki/apple-configurator-2.html

[obelix24]

I'm using trackpad. I haven't tried DFU

[obelix24]

mon2 I've tried DFU and I get successfully to DFU and restored the MacBook with another MacBook with apple configurator but still no backlight.
I tried to connect external display with HDMI and I can see the screen but I can not finish first setup as main screen is still on MacBook (even if I disconnect display cable) , as the Touch Bar is not showing anything I'm not able to switch displays

Do you know if Touch Bar from other MacBook (1708,1989 will work) ? are they interchangeable ?

may finishing setup enable somehow backlight ?

and yes keyboard and trackpad work (on the second screen only thing that is possible to do is connect to wifi)

[obelix24]

I've checked also
RP611 - LPDP_INT_HPD - 1,167V
RD560 - all pins 12,3V
CC720 - P3V3S2_FB - only - 0,7V
CC720 - P3V3S2_VOS - 3,3V

[mon2]

Not sure on the touch bar compatibility but as they are sold as different part numbers then there must be a difference. You can confirm by reviewing Aliexpress / Mobile Sentrix stores on the same.


https://youtu.be/O-kNBdxAo5w


With no power / no battery, what is the exact resistance to ground of PPVOUT_LCDBKLT ?

I believe that when you connect the HDMI external monitor, the unit will enter extended display mode as you are observing. The main functions are still local on the dark LCD till you make use of the non-working touchbar. Does the touchbar look to be damaged or cracked? In the end, it is just a fancy but high resolution rectangular LCD with a touch panel.

Carefully measure the voltage to ground of:

I2C_AOP_ALS_SCL
I2C_AOP_ALS_SDA

I2C_ALS_1V8_SCL
I2C_ALS_1V8_SDA

If this is not practical then remove all power (no battery); meter in DIODE mode.

Red meter probe (yes red) to ground. Black meter probe to the point to test from the above list. We are checking to see if the I2C lines that are low voltage variations for this M1 board are defective or not.

Post each measurement.

[obelix24]

battery and charge disconnected
PPVOUT_LCDBKLT - approx 5M ohms and falling down

I don't see any cracks or any damage on Touch Bar

I2C_AOP_ALS_SCL - 0,338V
I2C_AOP_ALS_SDA - 0,339V

I2C_ALS_1V8_SCL - 0,594V
I2C_ALS_1V8_SDA - 0,594V

[mon2]

Both of these power rails are of the wrong voltage. The 1v8 side should be parked by default @ 1v8. The lower voltage side of the same signals should be @ 1v25 for each. UD140 is a fet based voltage level translator between the 2 power planes.

[obelix24]

mon2 values are from Diode mode

[rany]

This model has many resistors around the backlight driver. Test each and every one of them to make sure they have the correct resistance, then lift them to make sure none of them has a corroded pin underneath the resistor.
Ask me how I know to check these very very carefully.
Same applies for the keyboard controllers by the way.

[obelix24]

ok yesterday I was working on this Mac and I was checking with thermal cam and UP700 was getting hot when it was turned on (still without backlight)
I've give it change and replaced UP700 from donor and MacBook turned on with backlight but still looks like not charging (showing battery 78% but not charging if I disconnect charger immediately MacBook turns off

[mon2]

Good. Measure the voltage to ground of each pin on the battery connector. Post each measurement.

[obelix24]

ok I've measured battery pins when battery and charger are connected :
I2C_SMC_PWR_3V3_SCL - 3,2V not stable falling to 2,8V
I2C_SMC_PWR_3V3_SDA - 3,2V not stable falling to 2,8V
SYS_DETECT_L - 0V

When battery is disconnected and charged is connected I've measured :
I2C_SMC_PWR_3V3_SCL - 3,2V stable (it's going from 3,251V to 3,249V)
I2C_SMC_PWR_3V3_SDA - 3,2V stable (it's going from 3,251V to 3,249V)

Also I have issue that Power button is working but Touch ID not.
Also camera is not detected.

Touch Bar starts working - I have to test it more.

battery is showing 12,10V and 0a in stats

[obelix24]

ok update. Battery is charging fine now.

Issue was that I didn't know that over battery connector (that one attached with screw) was missing one black part that was creating probably more pressure

So now I have 2 issues left.

1. Touch Bar is working but when I turn on MacBook it's black, I close the lid a reopen and Touch Bar is fully working
2. camera is not working. I was told by previous owner that it was working before.