Macbook A2289 Backlight Issue

[Instafixx]

Its a confirmed No Backlight Issue.

With Board on Desk and Display Connected :
R8442 is 3.3V. (Resistance across Pins is 0.3 Ohms)

Input Voltages to U8400 i.e R8444/5 are 5V stable.

Getting 12.6V on the Backlight Fuse as well.

Tried a different screen assembly as well.

 

[2informaticos]

Any history available?

Check diode mode to ground at K/D8410.

Be sure R8450-53 are all good.
Also check voltage and diode mode to ground at SCL/SDA lines.

 

[Instafixx]

Was checking D8410.
Pin 1 is .844
Pin 2 is 0.05 PPVOUT_S0_LCDBKLT_F

Removed D8410.

Should we inject voltage?

 

[2informaticos]

Tested disconnecting LCD assembly?

Voltage injection should help you to find the culprit.

 

[Instafixx]

D8410 was checked disconnecting LCD Assembly

 

[Instafixx]

Injected Voltage.
A cap was getting hot. Removed it.

Pin 2 is 2.9 PPVOUT_S0_LCDBKLT_F

Still no Back Light.

Do we need to replace D8410 as well?

Resistance Across Pins
R8450/1 is 0.5 Ohms
R8452/3 is 1.3 K Ohms.

DIODE MODE at SCL/SDA is .536

 

[Instafixx]

Replaced D8410. Solved