iphone 6 backlight problem

Hi guys , i got iphone 6 no back light.
I have removed shield and find diode burn . Removed diode and check if there are anything in short but all it is ok .
Replace diode and power one but diode burn again.
Removed again one time diode , after try to change coil , IC , and C1552 C1597.
Try to power on , and diode burn again.
Any can help me to find the problem?
I don’t have a short .