A3113 MBA M3 No Backlight after damage on LCD connector

[Vliegenier04]

Goodday,

I'm having difficulties (attemtping) to repair an 13.6" MBA M3 which suffered minor damage at the LCD connector (?). The backlight won't come on and I've measured only 0v at the backlight out pin off the connector. It seems the 45v (?) required to power the backlight isn't present on the board.

Also, the 20v fuse (F5601) was a little bit blown, so I've replaced that.

I can't seem to figure out what the issue seems to be, tried another display, measuring around the board but nothing stands out of the ordinary aside of the missing voltages on the backlight rail.

Where should I continue diagnosing?
Note, I'm working off an M2 MBA boardview & schematic (820-02536) so that isn't ideal...

~Vlie

 

[2informaticos]

Do you get image for sure, only missing backlight?
Did you test external video?

 

[Vliegenier04]

Not tested an external display (yet). I for sure see an Apple logo when plugging in the charger. I'll put on a external display and report back.

 

[Vliegenier04]

External display is functional.

 

[Vliegenier04]

Checked with display attached & backlight IC replaced: 1.6v

 

[2informaticos]

Check if backlight and video connector areas are closer to 820-02098 schematic/boardview.

 

[Vliegenier04]

Nope, not even close. I have a feeling it is connected to the display connector itself - does the backlight even power on/supply the 45v when there's no screen detected? It might have to do with that?

 

[2informaticos]

Video and backlight voltages, MUST be checked with LCD connected!

 

[Vliegenier04]

0.8v on backlight (PPVOUT_LCD_BKLT_D) and now I've got an short on PP3V8_AON. I'll measure around and let you know.