Chosen Solution
HI Everyone.. Hi @refectio Sir.. I have an iphone 7 for repair.. It is long story. Cliente sent me iphone with broken screen and in DFU MODE. When i try to reset it with itunes i have error 6. I reball NAND and phone reset perfectly. After resetting there is no image on screen. I check with new screen but the problem is same. I check all filter and found FL3901 damage. I dont have this filter ( im waiting new order) so i jumped it and try to turn on the phone. When i power on, i see the image (apple) only for few second and the problem come back. I check all filter.. everything is perfect. SO i check voltage on u3703 on all capacitor (c3711 to c3717) (I do this without connect screen) I have 6 volt only on c3717 , 16 and 15. From c3714 to c3711 no voltage. I putout the capacitor and check the voltage on the track but no voltage. Unfortunally i dont have new ic for the moment, so i just reball it but the problem is same. SO do u think the cause can be IC - u3703??? is this any ic on 6 or 6s series board who i can use on 7 board? Thanks a lot guys for attention
The blown filter was on the Anode line so I would focus my troubleshooting on the backlight circuit first. Do you see a dim image when shining a bright flashlight? If so, you may have to replace the entire backlight circuit (IC, Diodes). The coils are now in Trinity (M2800) so they may be damaged as well. If you can’t see an image, then troubleshoot the LCD driver first.
