iPhone 5 U3 IC / R20 - GSM-Forum

MrInformation · 09-26-2014, 19:07

I have a problem.

1) I received an iPhone 5 which lost these 3 chips

Q3, U3, and DZ101_RF

2) I reballed all of the components succesfully. I used 500 degree celcius
heat, and low air.
However when I put the phone together the HOME BUTTON WAS NOT
WORKING. But the power button was working fine.

I also replaced R20 and R22 with resistors from an iPhone 4S
I did not loose any pads.

I have also put the board in a phone that is fully functional
home button still does not work.

QUESTIONS

1) CAN ANYONE TELL ME WHY THE HOME BUTTON IS NOT WORKING

CAN ANYONE TELL ME WHY THE HOME BUTTON IS NOT WORKING

2) Also what Multimeter can I use to test tiny resistors like R20 ?

Olkowski · 09-26-2014, 19:22

PP1V8_ALWAYS check voltage 1V8 if not have U7 replace.

MrInformation · 09-26-2014, 19:29

I doubt there are any problems with the U7 PMIC.

Also the Power button is working.
When I took out U3 the power button stopped working when I put it back in the power button started working
again.

MrInformation · 09-26-2014, 20:05

Where on the board do I check PP1V8_ALWAYS.

Olkowski · 09-26-2014, 20:26

check on C285.Monday I check in logic board.500 degree celcius I think is to match.Maybe replace new one.

MrInformation · 09-26-2014, 20:33

Could I use these IC on iPhonee 3G: U11_RF, U35_AP and U39_AP

They have the same schematic but different voltage input and outputs.

MrInformation · 09-26-2014, 20:35

Quote:

Originally Posted by Olkowski

check on C285.Monday I check in logic board.500 degree celcius I think is to match.Maybe replace new one.

Remember the Power button still works.
And the Power button will not function without U3

I tested it.

Olkowski · 09-26-2014, 20:41

Q3 is for LCD.U3 is for Menu button I think.So check voltage 1V8 next U7 change its very hard.Better use MF70 Proxxon.

MrInformation · 09-28-2014, 16:36

okay check on Monday and let me know

laptopmd · 10-01-2014, 14:43

R20 and R22 are critical and they are unique value on iphone5 (392Kohm). I have tried to replace those resistors with other similar values and i had problems too (first home button not working, then it was too much sensible).
You should use same resistors from other iphone 5 board.

G1mobile repair · 04-30-2015, 20:29

Where can I buy R20 and R22 please

cal_guy · 05-01-2015, 00:13

500 Celsius heat and plastic sim socket never melted????

09-26-2014, 19:07	#1 (permalink)
MrInformation Major Poster Join Date: Mar 2011 Location: USA. Posts: 47 Member: 1536098 Status: Offline Thanks Meter: 4	iPhone 5 U3 IC / R20 I have a problem. 1) I received an iPhone 5 which lost these 3 chips Q3, U3, and DZ101_RF 2) I reballed all of the components succesfully. I used 500 degree celcius heat, and low air. However when I put the phone together the HOME BUTTON WAS NOT WORKING. But the power button was working fine. I also replaced R20 and R22 with resistors from an iPhone 4S I did not loose any pads. I have also put the board in a phone that is fully functional home button still does not work. QUESTIONS 1) CAN ANYONE TELL ME WHY THE HOME BUTTON IS NOT WORKING CAN ANYONE TELL ME WHY THE HOME BUTTON IS NOT WORKING 2) Also what Multimeter can I use to test tiny resistors like R20 ?

09-26-2014, 19:29	#3 (permalink)
MrInformation Major Poster Join Date: Mar 2011 Location: USA. Posts: 47 Member: 1536098 Status: Offline Thanks Meter: 4	I doubt there are any problems with the U7 PMIC. Also the Power button is working. When I took out U3 the power button stopped working when I put it back in the power button started working again. Last edited by MrInformation; 09-26-2014 at 19:38.

09-26-2014, 19:22	#2 (permalink)
Olkowski Freak Poster Join Date: Sep 2003 Location: Poland Age: 57 Posts: 147 Member: 40262 Status: Offline Thanks Meter: 11	PP1V8_ALWAYS check voltage 1V8 if not have U7 replace.

09-26-2014, 20:05	#4 (permalink)
MrInformation Major Poster Join Date: Mar 2011 Location: USA. Posts: 47 Member: 1536098 Status: Offline Thanks Meter: 4	Where on the board do I check PP1V8_ALWAYS.

09-26-2014, 20:26	#5 (permalink)
Olkowski Freak Poster Join Date: Sep 2003 Location: Poland Age: 57 Posts: 147 Member: 40262 Status: Offline Thanks Meter: 11	check on C285.Monday I check in logic board.500 degree celcius I think is to match.Maybe replace new one.

09-26-2014, 20:33	#6 (permalink)
MrInformation Major Poster Join Date: Mar 2011 Location: USA. Posts: 47 Member: 1536098 Status: Offline Thanks Meter: 4	Could I use these IC on iPhonee 3G: U11_RF, U35_AP and U39_AP They have the same schematic but different voltage input and outputs.

09-26-2014, 20:41	#8 (permalink)
Olkowski Freak Poster Join Date: Sep 2003 Location: Poland Age: 57 Posts: 147 Member: 40262 Status: Offline Thanks Meter: 11	Q3 is for LCD.U3 is for Menu button I think.So check voltage 1V8 next U7 change its very hard.Better use MF70 Proxxon.

09-28-2014, 16:36	#9 (permalink)
MrInformation Major Poster Join Date: Mar 2011 Location: USA. Posts: 47 Member: 1536098 Status: Offline Thanks Meter: 4	okay check on Monday and let me know

10-01-2014, 14:43	#10 (permalink)
laptopmd Freak Poster Join Date: Jan 2013 Location: Switzerland Age: 48 Posts: 408 Member: 1873863 Status: Offline Thanks Meter: 67	R20 and R22 are critical and they are unique value on iphone5 (392Kohm). I have tried to replace those resistors with other similar values and i had problems too (first home button not working, then it was too much sensible). You should use same resistors from other iphone 5 board.

04-30-2015, 20:29	#11 (permalink)
G1mobile repair Freak Poster Join Date: Nov 2011 Location: County Durham, UK Posts: 358 Member: 1696994 Status: Offline Thanks Meter: 24	Where can I buy R20 and R22 please

05-01-2015, 00:13	#12 (permalink)
cal_guy No Life Poster Join Date: Oct 2010 Location: Toronto, Canada Posts: 948 Member: 1430995 Status: Offline Sonork: 100.1613203 Thanks Meter: 312	500 Celsius heat and plastic sim socket never melted????