iPhone 6 backlight chip U1502 with missing pin - GSM-Forum

ozzyfrozzy · 02-28-2018, 10:10

Hi,

i have a iPhone 6 with a backlight problem.

I changed the backlight chip u1502 but when i removed it i lost 1 pin.

C2 is the missing pin.

is there a solution to jump or wire this pin on the motherboard?
i soldered the u1502 chip with the missing pin but didn't work.

thanks in advance

Joe025 · 02-28-2018, 11:00

You got bad luck :-(
Pin C2 on U1502 is connected to cpu

ozzyfrozzy · 02-28-2018, 11:08

)-: aw it happened after i removed the chip correctly. after i cleaned up with brush it just popped up.

Thank you for your answer. i guess its dead end then.

7Axis · 02-28-2018, 14:14

Well before dumping it you could try removing the CPU and making a jumper, it is possible just very hard, you would need to cure a 0.05mm jumper wire underneath the CPU with solder mask so it doesnt short with other pads, I've done similar repair before and was successful, what have you got to lose?

minho · 02-28-2018, 14:44

There is one possibility that hasn't been mentionned...

There is an external point of access, it's called PP1301. However, it is directly in between the PMIC (U1202) and CUMULUS (U2401). You would have to remove them both, make the jumper and put those IC's back in place. Still. this would be much easier than removing/reballing the CPU. Working on the CPU is a low probability repair unless you have done it many, many times successfully before.

ozzyfrozzy · 02-28-2018, 14:47

i understand that it is possible with jumper on the cpu pads but its not time/worth it. If i have enough time to do this repair i will think about it. I was thinking of a "simple" fix and not this much time taker fix.

Thank you for your idea. I appreciate it.

ozzyfrozzy · 02-28-2018, 15:02

where should i put the jumper from PP1301 to .. ?

nAthOs · 02-28-2018, 22:16

Just bridge between the pp1301 point and the c2 missing pad.

minho · 03-01-2018, 01:36

Quote:

Originally Posted by nAthOs

Just bridge between the pp1301 point and the c2 missing pad.

Exactly, you will have to run the jumper from PP1301 to the missing pad, secure it in place with UV-Curable mask so that when you reball the IC and solder it into place, it will properly connect to the jumper.

ORITECH · 03-01-2018, 02:41

just change the board, done

02-28-2018, 10:10	#1 (permalink)
ozzyfrozzy Junior Member Join Date: May 2017 Posts: 12 Member: 2716020 Status: Offline Thanks Meter: 0	iPhone 6 backlight chip U1502 with missing pin Hi, i have a iPhone 6 with a backlight problem. I changed the backlight chip u1502 but when i removed it i lost 1 pin. C2 is the missing pin. is there a solution to jump or wire this pin on the motherboard? i soldered the u1502 chip with the missing pin but didn't work. thanks in advance

02-28-2018, 11:00	#2 (permalink)
Joe025 Insane Poster Join Date: Jun 2013 Location: Germany Posts: 74 Member: 1959885 Status: Offline Thanks Meter: 6	You got bad luck :-( Pin C2 on U1502 is connected to cpu

02-28-2018, 11:08	#3 (permalink)
ozzyfrozzy Junior Member Join Date: May 2017 Posts: 12 Member: 2716020 Status: Offline Thanks Meter: 0	)-: aw it happened after i removed the chip correctly. after i cleaned up with brush it just popped up. Thank you for your answer. i guess its dead end then.

02-28-2018, 14:14	#4 (permalink)
7Axis Freak Poster Join Date: Nov 2017 Location: Canada Posts: 131 Member: 2777379 Status: Offline Thanks Meter: 34	Well before dumping it you could try removing the CPU and making a jumper, it is possible just very hard, you would need to cure a 0.05mm jumper wire underneath the CPU with solder mask so it doesnt short with other pads, I've done similar repair before and was successful, what have you got to lose?

02-28-2018, 14:44	#5 (permalink)
minho Freak Poster Join Date: Dec 2015 Location: Canada Posts: 113 Member: 2498972 Status: Offline Thanks Meter: 33	There is one possibility that hasn't been mentionned... There is an external point of access, it's called PP1301. However, it is directly in between the PMIC (U1202) and CUMULUS (U2401). You would have to remove them both, make the jumper and put those IC's back in place. Still. this would be much easier than removing/reballing the CPU. Working on the CPU is a low probability repair unless you have done it many, many times successfully before.

02-28-2018, 14:47	#6 (permalink)
ozzyfrozzy Junior Member Join Date: May 2017 Posts: 12 Member: 2716020 Status: Offline Thanks Meter: 0	i understand that it is possible with jumper on the cpu pads but its not time/worth it. If i have enough time to do this repair i will think about it. I was thinking of a "simple" fix and not this much time taker fix. Thank you for your idea. I appreciate it.

02-28-2018, 15:02	#7 (permalink)
ozzyfrozzy Junior Member Join Date: May 2017 Posts: 12 Member: 2716020 Status: Offline Thanks Meter: 0	where should i put the jumper from PP1301 to .. ?

02-28-2018, 22:16	#8 (permalink)
nAthOs Crazy Poster Join Date: Sep 2017 Posts: 54 Member: 2757091 Status: Offline Thanks Meter: 0	Just bridge between the pp1301 point and the c2 missing pad.

03-01-2018, 02:41	#10 (permalink)
ORITECH Registered User Join Date: Sep 2015 Posts: 213 Member: 2462860 Status: Offline Thanks Meter: 71	just change the board, done