Chosen Solution
I have a phone for repair it came in as no image problem with no backlight. After checking the phone, a capacitor for the backlight, C3903, was missing. Instead of replacing it, I bridged it together which was wrong choice because it burned the backlight filter FL3901 off the trace. So after replacing the capacitor C3903 I made a jumper and connected it to C3725, enabling the backlight to turn on. Now the problem is image. I don’t know where to start looking for the problem. Any response will be appreciated.
C3903 is a NOSTUFF component, meaning it’s not placed on the logic board. It’s in the schematic though and was probably used for development/testing purposes. So there is no need to replace it. The other thing is that you NEVER EVER bridge/short the contacts for a capacitor…that’s not how capacitors work. So you basically forced the output of PP_LCM_BL_ANODE to ground and blew the filter FL3901. Are you certain the backlight works? As for the LCD, this is the circuit you need to troubleshoot. Check for shorts on the outputs and then check for proper voltages.
And check the filters…
