820-2936 no backlight

[2informaticos]

Do you have image?
Post D9701 voltage (both pins) and Q9706.
Check F9700 and R0910.

 

[Kyle93]

D9701 pin 1 0.70V pin 2 0.67V

Q9706 pins 1,2,3,4,5 0V pin 6 12.60V

f9700 12.60V

r0910 0V

 

[Kyle93]

Q9706 pin 4 IS 12.60 V and the rest are 0V

 

[2informaticos]

Change Q9706.
Check first if no short to ground at pin 1.

 

[Kyle93]

no short on pin 1

changed. pin 1 12.60V pin 2 0V pin 3 0V pin 4 0v pin5 0v pin 6 12.25V

 

[2informaticos]

You are confused somehow.
Pins 1, 2, 5, 6 are common for Q9706...
Please be sure about provided information.

 

[Kyle93]

Yes sure about current provided information

 

[2informaticos]

"pin 1 12.60V pin 2 0V"
IMPOSSIBLE!!!
Pins 1 and 2 are common, as 5 and 6 too; all these (four) pins are directly connected inside the Q9706 package...
Please, look at the schematic.

 

[Kyle93]

mixed up measurements

pin 1 and 2 0v pin 5 and 6 0v pin 4 12.60V

 

[2informaticos]

Pin 3???
That controls the MOSFET...

 

[Kyle93]

pin 3 12.22V

 

[2informaticos]

"Do you have image?"
???

Post LCD_BKLT_EN, and voltage pins 2/3, 4, 6, 7 of J9000.
Measure always with LCD connected...

 

[Kyle93]

pins 2/3, 4, 6, 7 3.2v

LCD_BKLT_EN 0V

 

[Kyle93]

do not see image on the screen with flashlight. bad pch?

 

[2informaticos]

Try another screen.
Be sure no corrosion and good contacts at J9000.
L9080 OK?
Also test external video.

 

[Kyle93]

Is board un repairable then? Is it worth trying a new pch?

Vcore does start at 1.1V and then drop to 0.8

 

[Kyle93]

L9080 looks good but not getting any voltage

 

[Kyle93]

test screen is a known good screen

 

[2informaticos]

"Be sure no corrosion and good contacts at J9000.
--------------
Also test external video."

"pins 2/3... 3.2v"
Looks like screen is detected; you should also get image.

 

[Kyle93]

what about backlight?