iPad 6 A1893 backlight issue - GSM-Forum

thagangsta · 01-14-2020, 15:42

Hi,

iPad 6 / 2018 / A1893.
Problem: Randomly the backlight doesnt come on after pressing power or homebutton. The LCD itself does come on, so the ipad unlocks and whatever.

I've seen this problem before and within warranty apple swaps it as "mainboard issue". I suspect its drop/impact damage.

Nevertheless, this unit is out of warranty, but in mint condition.

Any advices where to begin debugging?...

Filters -> Diode -> Coil

Reference values.
Schematics.

Thanks

orx · 01-18-2020, 10:45

Hi

check solders joint on fpc connector

AIR2.jpg

thagangsta · 02-03-2020, 16:29

I found these readings.

Thanks to the original creater.

thagangsta · 02-03-2020, 16:31

For the moment, apparently the issue was caused by dirt inside the lcd connector.

Interesting for a never opened ipad.

bemol · 02-03-2020, 18:20

hi,

remove the black ribbon, some smd are under

chickenhawk88 · 06-24-2020, 20:22

Quote:

Originally Posted by thagangsta

I found these readings.

Thanks to the original creater.

What do the numbers/readings represent in the picture? resistance values ?

I have a ipad 6 with backlight issues. I replaced one diode so far and still same issue. I don't see anything obvious like caps burned by the display connector. I swap with good lcd/ digitizer with same result. TIA.

timvandenboo · 06-29-2020, 14:35

I replaced the backlight ic on two ipads 2018 last week that had on/off backlight problem.

Reading in one side of diode should be 230 other side 700 (orsomething) values can be found in phoneboard.

Backlight ic is the same as on ipad 2017

01-14-2020, 15:42	#1 (permalink)
thagangsta Freak Poster Join Date: Feb 2001 Location: Netherlands Age: 39 Posts: 313 Member: 3212 Status: Offline Thanks Meter: 10	iPad 6 A1893 backlight issue Hi, iPad 6 / 2018 / A1893. Problem: Randomly the backlight doesnt come on after pressing power or homebutton. The LCD itself does come on, so the ipad unlocks and whatever. I've seen this problem before and within warranty apple swaps it as "mainboard issue". I suspect its drop/impact damage. Nevertheless, this unit is out of warranty, but in mint condition. Any advices where to begin debugging?... Filters -> Diode -> Coil Reference values. Schematics. Thanks

01-18-2020, 10:45	#2 (permalink)
orx No Life Poster Join Date: Oct 2012 Location: Republic of Serenissima Posts: 1,516 Member: 1825965 Status: Offline Thanks Meter: 874	Hi check solders joint on fpc connector AIR2.jpg

02-03-2020, 16:31	#4 (permalink)
thagangsta Freak Poster Join Date: Feb 2001 Location: Netherlands Age: 39 Posts: 313 Member: 3212 Status: Offline Thanks Meter: 10	For the moment, apparently the issue was caused by dirt inside the lcd connector. Interesting for a never opened ipad.

02-03-2020, 18:20	#5 (permalink)
bemol Insane Poster Join Date: Apr 2012 Location: FRANCE Posts: 71 Member: 1744018 Status: Offline Thanks Meter: 14	hi, remove the black ribbon, some smd are under

06-29-2020, 14:35	#7 (permalink)
timvandenboo Freak Poster Join Date: May 2013 Location: Netherlands Posts: 376 Member: 1939450 Status: Offline Thanks Meter: 165	I replaced the backlight ic on two ipads 2018 last week that had on/off backlight problem. Reading in one side of diode should be 230 other side 700 (orsomething) values can be found in phoneboard. Backlight ic is the same as on ipad 2017