Chosen Solution
Hello, Greeting’s to everyone. I am struggling with Iphone 6 plus. The phone turns on , is recognized by itunes and the backlight is working also.. But there is no image at all on the LCD.. Phone is not water-damaged - the indicator’s look white and clean. Also under microscope did not found any damage to board. Could someone give me some hint’s what to do next ? Chestnut (U1501) ? Update (04/05/2018) Update. I have measured up the lines which should be responsible for image.. PP_VCC_MAIN - 3,6 V ( measured on C1554) P6V0_LCM_BOOST - 6V (measured on C1502) PN5V7_SAGE_AVDDN - 5,7 V (measured on C1504) P5V7_SAGE_AVDDH- 5.7 V (measured on C1577) PP5V7_LCM_AVDDH - 5,7 V (measured on C1569) PP5V1_GRAPE_VDD - 5,1 V (measured on C1541) What i should test next ? Update (04/06/2018) Hello, So i did a new measurements today again with fresh head. The result is the same except : PN5V7_SAGE_AVDDN - minus 0,37 (measured on C1504) So i have a short on that line. So the options are for me : 1)C1504 ; FL2061; C2044 or can it be the chestnut himself? Thank you for your attention. Update (04/07/2018) Hello to everyone, Happily i was enable to find out the shorted caps (it was C2049) removed it from the board and voila image on lcd ! Big thanks to Minho for helping.
Chestnut appears to be working well, now you have to check the LCM filters if you haven’t already.
Since you are asking about a motherboard related problem I assume you’ve already tested with a good working screen. Having backlight means that the phone it detects the screen and its sending data/image to be displayed. Probe around the U1501/Chesnut chip for shorts, if none found replace the chesnut.
