820-2936-B No backlight

[Triple6r]

Hi guys iam new here . In the past i fixt a lot of old mackbook airs 2008-2009 made a money with it. After a few airs that i cannot fix i look closer and start learning and watching day in day out louis his youtube channel.i bought a macbook pro with no backlight to start learning
i start looking at the schematics for this model 820-2936
i got 12,6 dc on F9700 it was the first thing a put my fluke on
i got nothing on c9796 olso
can you guys tell me what to look for
it has no waterdamage
greetings triple6r

 

[dukefawks]

12V on F9700 is not enough info. You should measure if 12V is on both sides to make sure it is not blown.
Is there an image on the LCD? Was this liquid?

 

[Triple6r]

Hi pin 1 from F9700 is 12.60 and on pin 2 4.330?
Yess there is an image. No no liquid
thnxs

 

[dukefawks]

So the fuse is blown. This happend because of a short on the backlight output. Measure resistance to GND on C9796.

 

[Triple6r]

Hi i measure it and it go's from 0,640 slowy upward 0,644 06.48 and more

 

[ALB-Repairs]

someone probably blew the fuse, carefully insepct the screen cable and connector, if nothing seems wrong replace f97000 and see what happens

 

[Triple6r]

Hm i have put other screen on it and same problem and i put a light on de back of the screen and go to webcam and that olso not working?

 

[dukefawks]

Replace the fuse and see if backlight works.

 

[Triple6r]

I did replace it it got backlight now but nou only got white screen it start up it chaims i here donggg ?? Did i hit something with replacing the fuse

 

[dukefawks]

Hold down the ALT key while turning it on. Disconnect any HDD. Do you get a boot menu? If not what is the voltage on C9015?

 

[Triple6r]

Hi i have done the alt key etc dont work. I have 0 on c9015 pin 1

 

[dukefawks]

So no power to the LCD. I bet L9004 is fried. Check for a short on C9015 first before replacing it of course. LCD plugged in!

 

[Triple6r]

I see that i got a strange looking L9004 ? Can that be the problem but how can that be before i got image no backlight now i got backlight no image

 

[Triple6r]

Same time haha

 

[Triple6r]

I got 0.9m ohms

 

[dukefawks]

0.9m as in milli or Mega? If low then unplug LCD and see if short is gone. Inspect cable/connector for damage.

 

[Triple6r]

I unplugd lcd cable now i getting 2,043 k ohms before mine fluke on same mode 0,9 m ohms

 

[ALB-Repairs]

sounds like you are measuring to GND and not measuring across the suspect component.

Measure across pin 1 and 2 of the component

 

[Triple6r]

I got when i measure across pin 1 and 2 with lcd cable 4.216 k ohms (c9015)
and with no lcd cable plugd 204.4 k ohms

 

[ALB-Repairs]

the components bad then, replace it, it should restore the diaply