iPad 6 A1893 Intermittent Back Light, No back light. - GSM-Forum

Insight411 · 10-01-2020, 13:14

Intermittent Back Light, No back light.

Symptom: Backlight will intermittently work. Using the flashlight test confirming the LCD is working normally.

Disconnect the battery. Connect lightning cable. Apple logo will appear and will be backlit. It’s normal for the iPad to boot loop with the battery disconnected. When the Apple logo appears reconnect the battery. iPad will boot and work normal until the lightning cable is removed or power button is pressed and iPad is off for more than a few seconds.

VCC is present on the anode of the back light diodes but it is missing the square wave from the back light driver IC when the fault occurs. No square wave, no 18 volts on the cathode, no back light. The square wave when present measured 25 volts p-p. Serviced three iPad 6’s with the above symptoms and replacing the back light driver IC repaired all three. The driver IC is located between the two backlight coils.

timvandenboo · 10-01-2020, 13:30

Do a visible inspection on the coils and diodes. Interchangeable from an ipad air 1. If looking good. Change backlight ic. (same as ipad 7 2018, pro 10.5)

10-01-2020, 13:14	#1 (permalink)
Insight411 Junior Member Join Date: Sep 2020 Location: North Carolina Posts: 1 Member: 2968751 Status: Offline Thanks Meter: 0	iPad 6 A1893 Intermittent Back Light, No back light. Intermittent Back Light, No back light. Symptom: Backlight will intermittently work. Using the flashlight test confirming the LCD is working normally. Disconnect the battery. Connect lightning cable. Apple logo will appear and will be backlit. It’s normal for the iPad to boot loop with the battery disconnected. When the Apple logo appears reconnect the battery. iPad will boot and work normal until the lightning cable is removed or power button is pressed and iPad is off for more than a few seconds. VCC is present on the anode of the back light diodes but it is missing the square wave from the back light driver IC when the fault occurs. No square wave, no 18 volts on the cathode, no back light. The square wave when present measured 25 volts p-p. Serviced three iPad 6’s with the above symptoms and replacing the back light driver IC repaired all three. The driver IC is located between the two backlight coils.

10-01-2020, 13:30	#2 (permalink)
timvandenboo Freak Poster Join Date: May 2013 Location: Netherlands Posts: 376 Member: 1939450 Status: Offline Thanks Meter: 165	Do a visible inspection on the coils and diodes. Interchangeable from an ipad air 1. If looking good. Change backlight ic. (same as ipad 7 2018, pro 10.5)