820-00244 no display and no backlight

[dudipupan]

Hi,
i got a A1534 (820-00244) that came with no backlight. When I opened it i saw that it was opened before and the lcd connector on the board was ripped off and backlight fuse was replaced.
So Replaced the lcd connector then i got an image but no backlight.
After some measurements around U8401 I suddenly don't get an image anymore but the system is still booting I already checked the LCD connector bit it looks soldered good.
PP5V_S0S2 is going up for a sec when plugging it in.

 

[dudipupan]

*PP5V_S0SW_LCD

 

[2informaticos]

DP_INT_HPD pulses at same time?

I bet for bad contacts.
Did you try known good LCD assembly?

 

[dudipupan]

unforunately DP_INT_HDP is not accessible (hidden behind cpu glue).

I resoldered the connector 2 times now and double checked the contact but i got the same result.
Unforunately i dont have a known good LCD for this model...

 

[dudipupan]

DP_INT_HDP is not pulsing

 

[2informaticos]

The signal comes from LCD; need to test with known good one.
Must go high at same time when 3V3/5V_S0SW_LCD appear.