820-02020 keyboard backlight not same brightness

[Dozer]

was liquid damage, but the board looks clean, the liquid i found in the fingerprint sensor and in the lcd driver board.

after replace the lcd and cleaning the fingerprintsensor connector all is working good.

it seems only that the brigtness left and right side is much more than in the middle of the keyboard.
I replaced the topcase for testing and there is the same problem (but topcase had liquid damage too)

so is it possible that here could be the backlight damaged or could it bee more tha mainboard, checked all the aereas aound the 3 connecors but seems super clean

 

[Dozer]

I read in Diode mode on JT002 without connected any of the 3 cables

1 1
2 1
3 1
4 .624
5 .624
6 .613
7 .613
8 1
9 1
10 1

JT001

1 .448
2 .448
3 1
4 1
5 1
6 1


JT000

1 .449
2 .449
3 1
4 1
5 1
6 1

connected all 3 cables

the readings are almost the same

JT001 has 2x 0.450 and
JT000 has 2x 0.450

JT003 has the same like before

 

[2informaticos]

Check RP910/1 values.

 

[Dozer]

both 10.7Ohm

 

[2informaticos]

Check if SMC reset helps.

 

[Dozer]

i tryed it by holding more than 10 sec the power button down. it not helped

i dimmed it to take a foto, hope its to see what i mean

 

[2informaticos]

JT000/1 have both only one LEDs strip.
JT002 has 2 LEDs strip, each one in series with JT000, or JT001.
The current which passes through JT000+1/2(JT002) must be equal with current through other 1/2(JT002)+JT001.
Unless there is a problem with RP910/1, or UP800.
But having same backlight on JT000/1 areas, current should be equal.
You may have problems with the backlight sheet behind the keyboard.

 

[Dozer]

i got today the new backlight sheet and now the right side is dark, the foil is new, so can that be that the foil is broken?

 

[2informaticos]

Very likely bad foil, if you get different behavior...

 

[Dozer]

today got the second new foil. and now its ok, that was the problem, a bad foil and a bad new foil.

thanks for help, case is solved

 

[2informaticos]

Thanks for feedback.
This may help other forum members in the future.