MacBook Pro 13" 820-3115

hamed57

New member
I have a macbook pro 13" with no backlight.
Everything else is working well.

My measurements:

backlight fuse: 12.55v
LVDS pin 21 and pin22: 12.54v
C9020 pin1: 12.52
C9020 pin2: 0.0

Board looks good under the microscope. I ultrasonic cleaned it and I slightly reflowed U9701.

Any hint at this point?
 

aprendiz

Moderator
Do you have image on the screen?? is yes check continuity between cathode of D9701 and ball A5 of U9701.....
 

hamed57

New member
Do you have image on the screen?? is yes check continuity between cathode of D9701 and ball A5 of U9701.....

Hi, Thanks for the reply,

I have image on the display.
There is continuity between cathode of D9701 and ball A5 of U9701.
 

aprendiz

Moderator
all seems to be ok but U9701 is not boosting, replace U9701, when take off the IC, confirm continuity on feedback line.....
 

dukefawks

Administrator
Diode mode on the BKL output line? D9701 check for short? All the voltages are there so it must be in the U9701 boost circuit.
 

hamed57

New member
Diode mode on the BKL output line? D9701 check for short? All the voltages are there so it must be in the U9701 boost circuit.

Hi, I don't know where can I get the measurement for "Diode mode on the BKL output line"
I did the diode mode between pin 21 and 22 and the ground and voltage drop is 0.605v
The is no short on D9701
 

dukefawks

Administrator
No continuity between PPVOUT_SW_LCDBKLT_FB and pin 2 of l9701, look at diagram and tell me if this is correct or not.
Need to check continuity between LP8550 pin B1,B2 and L9701. Also pin A5 to D9701 K cathode.
 
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