[SOLVED]iPhone 6s no image

[Bytesize]

Hi, this thing is trolling me, the phone was water damaged and c4200 was corroded and barely holding on, changed it and no joy, checked D4020 and it's fine, attached the screen and checked chestnut, 6v0 was present, 5v7 was there -5v7 was low at -3v2, I replaced chestnut and voltages are fine and 5v1 is also present, coil L4020 reads 1ohm as expected, can you point me in any other direction? I am getting backlight

 

[jessa]

Use your brain. You are troubleshooting image. Where does image have to end up? At the connector. Stare at the connector on the schematic and figure out what lines are most likely related to image as opposed to the other functions routed through the 6s lcd/digitizer connector. Of the ones you think might be related to image, divide them into "image power" and "image data" Now start with power---how can these lines fail? A--short to ground, B--lack of continuity, C--bad chip, no voltage was ever produced for these lines. Rule these causes out for each line one by one. Figure it out.

 

[Bytesize]

thanx jessa, turned out to be filter FL4205 which was showing continuity and beeping just fine but replaced it anyway and all was good in the world of board repair again, seriously trolling me as everything was reading exactly what it should have been, it should have been working but the filter that read good but must have been bad, lesson learned and will be looking for that in future.

Data recovered and another happy customer