820-4924 backlight issue

[Jay]

this came in dead, no power. Found corrosion around thunderbolt port. Cleaned and replaced what was bad and unit now powers on and passes all tests I throw at it. The backlight acts a little funky though.

Backlight only activates once progress bar starts loading under the Apple logo, not before that.

Alt-boot, during hardware test and as mentioned the first 5-10 seconds of boot it stays off. Once it kicks in it stays on.

SMC reset and PRAM reset didn’t fix it.

Any thoughts?

 

[dukefawks]

Does this have the wrong LCD assembly on it? 2015 models and newer are different and will cause backlight problems like this.

 

[Jay]

Can't say for sure, history of the machine is unknown. I have an Early 2013 display, can I use that to test on this Mid 2014?

 

[dukefawks]

4924 is a 2015 model! Get a known working 2015 model LCD for testing.

 

[Jay]

This is a MacBook Pro (Retina, 13-inch, Mid 2014), would a 2013 display work?

 

[Alan.L]

This is a MacBook Pro (Retina, 13-inch, Mid 2014), would a 2013 display work?

you will need a late 2013 display.

early 2013 display use logic board same as 2012
late 2013 display use same logic board as 2014

 

[Jay]

Thanks, will see if I can get my hands on one of those.

 

[aprendiz]

Come on guys, the board is a 820-4924 so it is a 2015 board!!, not 2012, not 2013, not 2014 but 2015!! So get a known good "2015" LCD assembly to test..

 

[dukefawks]

I guess they like to ignore my advice and keep messing about....

 

[Jay]

Hope you don't mean me by "they"

 

[bjf]

Yeah, this is the exact behavior of a late 2013/2014 screen on a 2015 820-4924 board. Should be good once you get the right screen on there.