MacBook Air 11" 2010

[myiannakou]

Hello.
I'm getting display from an external monitor but not from the LCD.
Shining a light through the back of the screen does not show up any icons etc.

Without having a test screen to try what's the best way to determine if it's the logic board or the LCD? I've measured the voltage at pin 1 of the LVDS on the board and there is .09v

I don't want to remove the board at this stage as I'm not even sure that the customer can afford the repair costs and therefore can't tell you the exact board number.
Thank you

 

[2informaticos]

Start posting accurate information.
What is the 820-xxxx code of your board?

Measure diode mode to ground on power lines of LCD connector, w/ and w/ screen connected.

 

[myiannakou]

I don't want to take the board out so can't give you the board number - sorry.

Here are the diode measurements for the first 6 pins (pins 1 - 6), hopefully this should help you

Without LCD | With LCD
Pin1 - 0.545 | 0.545
Pin2 - OL | OL
Pin3 - 0.587 | 0.587
Pin4 - 0.587 | 0.587
Pin5 - OL | OL
Pin6 - 0.614 | 0.614

There appears to be no difference between having the screen attached or not.

Bad screen??

 

[2informaticos]

I suppose you have 820-2796 board.
Is so dificult to use Google?

I was expecting diode mode readings on pins 3 & 18 of J9000.
Also post their voltages, as for pin 14 too.

 

[myiannakou]

Thank you

With screen
pin3 = 0.589
pin14 = 0.494
pin18 = 0.552

Without screen
pin3 = 0.587
pin14 = 0.524
pin18 = 0.552

Volatages
pin3 = 0v
pin14 = 0v
pin18 = 3.31v

 

[2informaticos]

If pin 18 gets steady 3V, then pin 14 should go high too.
If not, then try known good LCD assembly.

 

[myiannakou]

OK thanks again for your help!