Smartphone & Pad Repair Guide IPad Air3 A2134 startup dark screen without backlight repair The measured voltage, inductors L82P0, L82R0 and diode D820D82P0 are all supplied with VCC 4V, but there is no boost. The large inductor and two diodes are directly replaced, and the base is back to 500, which is normal.yx2023-02-03