(347) 552-2258 [email protected]

Macbook Air 802-00165-A Good backlight fuse, bad wled?

brooke.j

brooke.j

Member
I plugged the display back in and no backlight fuse blew. When I first turned on the computer pin 3 of connector was at 7.6v then slowly it went down to 1.6. Do you still think this is due to the display?
 
A

aprendiz

Moderator
The reason of a blown fuse is because a short on that line, this is why blew the fuse as you described on post #12...

Still think it is a bad display and/or cable..
 
brooke.j

brooke.j

Member
cool thx I'll see if I can pull a screen. I wish there was a spreadsheet on which screens you can interchange. Google fu is not turning up many hits.
 
larossmann

larossmann

Administrator
Staff member
any air screen can work on any other air. do not substitute a screen from any other unibody macbook or retina here or it will fuck everything up.
 
brooke.j

brooke.j

Member
Thx Louis I remember that now from one of your videos. Wasn't going to even try because I do watch and listen.
 
D

dukefawks

Administrator
Right lets start over here.

What is the voltage on pin 3,4 on LCD connector. LCD plugged in of course on not with the lid closed.
 
brooke.j

brooke.j

Member
Totally let's start over LOL! Ok so Pin 3,4 is 7.6V But as the board is left on it slowly drops. This must be the sleep Feature? Just FYI there is no HD installed. I have one if that makes it better?
 
Last edited:
brooke.j

brooke.j

Member
I have the LCD Plugged in. SMC_LID is 3.4v, PIN 3,4 of LCD is 8.5v. So it looks like the lcd is getting too much?
 
brooke.j

brooke.j

Member
Ok so I'l start over. Thank you again for all the help. This is with the LCD plugged in.

Q7707 PIN 2 = 3.4v, PIN 5 = 3.4v
LCD connector PIN 3,4 is 8.5v
SMC_LID = 3.4v
Q7706 PIN 3 = 2.8v (close enough right?) PIN 1,2,5,6 = 8.5v
 
Last edited:
brooke.j

brooke.j

Member
I've also cleaned the dam WLED driver too much and now if I wanted to replace it I don't know which way it goes. Can anyone help with that? Thx
 
brooke.j

brooke.j

Member
Ok I didn't see that post sorry I'll check those. Just a thought... there is only one LP8550 on mouser? Just want to make sure I got the right one. The numbers on top are different than on the original WLED.
 
D

dukefawks

Administrator
BKL_PWM should be higher. Do a PRAM reset to be sure it is not that first. Then check resistance to GND on BKL_PWM.
If that all seems ok, remove R7704 and connect BKL_PWM to 3V somewhere, like C7711 and see if that brings it back.
 
brooke.j

brooke.j

Member
Thanks duke for hanging in there with me. I'll get on that right away. This forum and you super awesome!
 
You must log in or register to reply here.
Top