Macbook A2141 820-01700 no image

[PITERPENY]

Hello! A little liquid got onto the 8500 connector, which led to a short circuit in the EDP_INT_AUX_N line in the U9850 . according to the scheme U9850 is identical to the MacBook A1707 820-00928 and I took it from this board and replaced it! (maybe they are not interchangeable? Tell me, otherwise the markings on them are different but according to the scheme they are identical)! I checked the display works on A1707. The cable was replaced and installed from A1707. (as I understand, on A2141 you can install a cable from A1707-A1990, but not vice versa). MacBook works with external display!

[PITERPENY]

[PITERPENY]

[mon2]

Check the voltage to ground of LCD_MUX_SEL.

Check the voltage to ground of LID_OPEN_SMC_IN. Open the lid of the laptop -> measure this voltage.

[PITERPENY]

Are these chips interchangeable?
LCD_MUX_SEL=53,3kohm(diod mode=1.107)
LID_OPEN_SMC_IN=47.7kohm( diod mode=0.426)

[mon2]

The part is pin for pin and appears to be only a standard MUX (multiplexer). I would conclude yes.

Requested the voltage to ground measurements (not resistance / not diode mode). We are checking if the logic levels (voltage) are present for the requested pins that select A or B side of the mux to the output.

[PITERPENY]

I apologize for the misunderstanding!
LID_OPEN_SMC_IN=1.8 v
LCD_MUX_SEL=0v ((board on the table, display not connected) is this voltage present without a connected display?

[mon2]

Yes, connect the lcd.

https://www.ifixit.com/Answers/View/...ternal+is+fine!

[iMuhtaseb]

chips are interchangeable yes

[PITERPENY]

chips are interchangeable yes

thanks for the direct answer!

[PITERPENY]

Yes, connect the lcd.

https://www.ifixit.com/Answers/View/...ternal+is+fine!

Today I bought a new LCD for this MacBook but it won’t turn on either! The screen is always black and there is not even a backlight!

[PITERPENY]

The part is pin for pin and appears to be only a standard MUX (multiplexer). I would conclude yes.

Requested the voltage to ground measurements (not resistance / not diode mode). We are checking if the logic levels (voltage) are present for the requested pins that select A or B side of the mux to the output.

it was not easy! but I measured the voltage with the display connected.
LCD_MUX_SEL=0.004v
LCD_MUX_SEL =0.502(diod mode)
LCD_MUX_SEL=4,59 kohm

[mon2]

Have you reset NVRAM & SMC?

[PITERPENY]

Yes, sure !

[PITERPENY]

no ideas ?

[mon2]

Does this logic board work with an external display? Use a type C dongle with a HDMI port for testing.

Does the caps key LED toggle?

What is the current & voltage draw when the unit is powered by an external adapter? Need to confirm if the logic board is working or not.

[PITERPENY]

Does this logic board work with an external display? Use a type C dongle with a HDMI port for testing.

Does the caps key LED toggle?

What is the current & voltage draw when the unit is powered by an external adapter? Need to confirm if the logic board is working or not.

in the first post I indicated that the MacBook works with an external monitor)

[PITERPENY]

The MacBook is fully working and charging, there is only no image on the built-in display!

[PITERPENY]

Hello! A little liquid got onto the 8500 connector, which led to a short circuit in the EDP_INT_AUX_N line in the U9850 . according to the scheme U9850 is identical to the MacBook A1707 820-00928 and I took it from this board and replaced it! (maybe they are not interchangeable? Tell me, otherwise the markings on them are different but according to the scheme they are identical)! I checked the display works on A1707. The cable was replaced and installed from A1707. (as I understand, on A2141 you can install a cable from A1707-A1990, but not vice versa). MacBook works with external display!

right here

[PITERPENY]

why is everyone ignoring me?