820-00138-a backlight issue

[gadgetfix]

Hey guys.

This macbook has backlight issue. When it came in it had no backlight. After sometime display came back - and then started flickering on and off pretty fast for about 10-20 seconds. So i guess whatever the issue was on its way out. Now black screen when i shine a torch can see visual.

I measured

12.67v on ppbus
3.42v present smc_lid

i get 0v on both sides of D7701 AND L7710
however d7720 and l7720 have 5v on both sides

is this faulty u7701?

 

[2informaticos]

First check F7700 and resistance to ground at both pins of D7701.
Post U7701 voltage at pins 5, 18, 17, 11.
Did you try known good LCD assembly?

 

[gadgetfix]

hey there,

backlight is back and hasnt disappeared since. i have done heaven for around 2 hours... not sure what it was but there was alot of dust... maybe that was the issue?

 

[2informaticos]

Maybe bad contacts on LCD connector...