Chosen Solution
Hi Guys.. I m here again for expert advises and for learn reparing :) My client sent me iphone 6s wth no image. The phone is second hand, so they dont tell me anything about phone history. I check with new display but the screen remain black, itunes recognize phone. I search on web and found this video https://www.youtube.com/watch?v=dYbW35dl… Try to putout C4200. fortunately the first component (c4200) is shortage and i solve the problem. Obviously you are thinking, if everything is ok, why i m here, :))) I m here because i want to learn and understand how find the problem on the phone and not just solve the problem searching in net or putting out every component. My question is : In this case, which is the first step. Before searching on the web i check if the backlight is present, i check all backlight filter, check FPC connector if damage. MY proper question is this line DISPLAY POWER PP5V7_LCM_AVDDH must have 5 volt??? so i check a phone who run perfectly (without lcd / touch panel) If there is no problem in the phone, i find 5 volt here (c4200)? Which is the right way to proceed in this case, if i have only schematic and not INTERNET :) Thanks a lot for attention.
Being a 6s, I agree… first checking phone boots and connects to itunes… is drawing proper current with DCPS or just check Ameter. Then Disconnecting battery and then screen, I check the FPC pins in Diode mode. In most display cases and backlight.. this will help guide you to the right location for repair. The 1v8, 5.7 and -5.7 lines must be there as well as several other voltages but starting with Diode mode measurements against the ZXW Seat resistance chart really helps speed things up most of the time :)
