iPhone 7 Audio IC remove suggestion - GSM-Forum

Sakalalina · 09-07-2018, 19:56

Hi,
it's the time to remove an audio IC from iPhone 7 for me, so before start i will ask you some tips and suggestion like temperature...

I'm not at my firs BGA work, i usually change without problem small BGA components like U2 in iPhone 6/6s, but this will be the first time i have to change a larger bga ic...

many thanks to any reply!

CDMA_RASHID · 09-09-2018, 06:28

Be careful with the heat.

Over heating can cause loss of Modem Firmware as the Baseband CPU is located just on the other side of the board.

I would recommend use preheater to heat the board upto 150 degree and use rework station with 300 degrees with medium airflow.

Or you can use Kepton tape to cover other parts while you remove Audio chip.

Or alternatively you can use high watt soldering iron with a broad tip and a good amount of solder and Flux to desolder the chip.

Hope that helps.

Sakalalina · 09-10-2018, 14:19

Quote:

Originally Posted by CDMA_RASHID

Be careful with the heat.

Over heating can cause loss of Modem Firmware as the Baseband CPU is located just on the other side of the board.

I would recommend use preheater to heat the board upto 150 degree and use rework station with 300 degrees with medium airflow.

Or you can use Kepton tape to cover other parts while you remove Audio chip.

Or alternatively you can use high watt soldering iron with a broad tip and a good amount of solder and Flux to desolder the chip.

Hope that helps.

Many thanks!
I know the high watt soldering technique but it never went well to me...
I will try to preheat the audio ic at 150° for one/two minutes and then remove it at 300°...thanks for the suggestion...

I have a question...
I've see that the problem is just a broken track from an outside ball of the IC, and a capacitor..
Do you think is possible to just insert a small wire under the audio ic, without removing it, touch the right ball pin, and do the jumper to the capacitor?

Sorry for my English, i hop you understand...

Sakalalina · 09-11-2018, 21:34

320° work for me...
but i think I've definitely damage the iPhone...many pin are missing...
using PADSviewer I've see that all the missing ping goes to the same net, and some of other pin of the same net are save, so maybe the iPhone is not totally dead...

Next week i will receive the audio IC and i will try to resolder it...i hope...

CDMA_RASHID · 09-11-2018, 21:50

Most of the dislodged pads are NC. So not to worry about them.

You should order UV Curable solder mask it helps in holding down the jumper wires in place.

Next time try not to scrap the ground near the tracks. It really messes up and shorts the tracks while soldering jumperwire.

I guess you can use the same Chip by reballing it. Most of the times the problem is not due to the Chip itself it is due to the broken pads underneith.

Best of luck.

Sakalalina · 09-18-2018, 13:28

Quote:

Originally Posted by CDMA_RASHID

Most of the dislodged pads are NC. So not to worry about them.

You should order UV Curable solder mask it helps in holding down the jumper wires in place.

Next time try not to scrap the ground near the tracks. It really messes up and shorts the tracks while soldering jumperwire.

I guess you can use the same Chip by reballing it. Most of the times the problem is not due to the Chip itself it is due to the broken pads underneith.

Best of luck.

Unfortunately i was not lucky...
After the Audio IC replacement the iPhone stop working and not turn on...
I think i have to improve my skill before try again with a similar IC...
Many thank for your help and suggestion

Sakalalina · 09-25-2018, 08:27

Quote:

Originally Posted by CDMA_RASHID

Be careful with the heat.

Over heating can cause loss of Modem Firmware as the Baseband CPU is located just on the other side of the board.

I would recommend use preheater to heat the board upto 150 degree and use rework station with 300 degrees with medium airflow.

Or you can use Kepton tape to cover other parts while you remove Audio chip.

Hope that helps.

I'm here again...
I've seen that many people don't use preheather and set the hot air temperature to 360-380°...
Do you think that is safe?

christina_ · 09-25-2018, 21:25

I use 330 and i have done 20+

Sakalalina · 09-26-2018, 07:15

Quote:

Originally Posted by christina_

I use 330 and i have done 20+

with o without preheather?
I'm trying to understand why my iPhone 7 is dead after audio ic replacement...

CDMA_RASHID · 09-26-2018, 08:36

What is the power consumption of the phone on DCPS.

Try removing the Audio Chip.

Lot of times the chip gets short. Or maybe pads underneith got shorted cause of miss alingment.

If the phone was working before soldering back Audio chip. It is most probably case of it.

Even if you over heat the board it would have no baseband but phone would not go dead.

Hope that helps.

Sakalalina · 09-26-2018, 15:40

Quote:

Originally Posted by CDMA_RASHID

What is the power consumption of the phone on DCPS.
Try removing the Audio Chip.

Lot of times the chip gets short. Or maybe pads underneith got shorted cause of miss alingment.

If the phone was working before soldering back Audio chip. It is most probably case of it.

Even if you over heat the board it would have no baseband but phone would not go dead.

Hope that helps.

Audio IC removed and cleaned all pad, the iPhone still not power on but the consumption are 130-140mAh at 4.2v

After all that trouble, i will fer you a virtual beer

CDMA_RASHID · 09-26-2018, 20:50

Is that consumption after pressing power key or it is consuming that much after directly connecting to DCPS ?.

Sakalalina · 09-26-2018, 21:22

Quote:

Originally Posted by CDMA_RASHID

Is that consumption after pressing power key or it is consuming that much after directly connecting to DCPS ?.

50mAh without the power button pressed,
130-140mAh after the power button is pressed

christina_ · 09-30-2018, 19:14

Quote:

Originally Posted by Sakalalina

50mAh without the power button pressed,
130-140mAh after the power button is pressed

Try to restore
and tell me error code. After that we will proceed.
how did you remove IC? how did you cover nearby ic from heat?
Please tell all details

Sakalalina · 10-04-2018, 13:37

Quote:

Originally Posted by christina_

Try to restore
and tell me error code. After that we will proceed.
how did you remove IC? how did you cover nearby ic from heat?
Please tell all details

Unfortunately it's no more recognizable form PC...even with the DFU sequence...
I've remove the IC with 330° and medium air, and i've use kapton tape and metal shield for cover nearby ic...

I think i have damage the CPU...
Maybe i can send the mainboard to someone with more skill to check it...

09-07-2018, 19:56	#1 (permalink)
Sakalalina Freak Poster Join Date: Feb 2014 Posts: 185 Member: 2127758 Status: Offline Thanks Meter: 26	iPhone 7 Audio IC remove suggestion Hi, it's the time to remove an audio IC from iPhone 7 for me, so before start i will ask you some tips and suggestion like temperature... I'm not at my firs BGA work, i usually change without problem small BGA components like U2 in iPhone 6/6s, but this will be the first time i have to change a larger bga ic... many thanks to any reply!

09-09-2018, 06:28	#2 (permalink)
CDMA_RASHID No Life Poster Join Date: Jul 2008 Location: Mumbai Age: 36 Posts: 1,023 Member: 821646 Status: Offline Thanks Meter: 507	Be careful with the heat. Over heating can cause loss of Modem Firmware as the Baseband CPU is located just on the other side of the board. I would recommend use preheater to heat the board upto 150 degree and use rework station with 300 degrees with medium airflow. Or you can use Kepton tape to cover other parts while you remove Audio chip. Or alternatively you can use high watt soldering iron with a broad tip and a good amount of solder and Flux to desolder the chip. Hope that helps.

09-11-2018, 21:34	#4 (permalink)
Sakalalina Freak Poster Join Date: Feb 2014 Posts: 185 Member: 2127758 Status: Offline Thanks Meter: 26	320° work for me... but i think I've definitely damage the iPhone...many pin are missing... using PADSviewer I've see that all the missing ping goes to the same net, and some of other pin of the same net are save, so maybe the iPhone is not totally dead... Next week i will receive the audio IC and i will try to resolder it...i hope...

09-11-2018, 21:50	#5 (permalink)
CDMA_RASHID No Life Poster Join Date: Jul 2008 Location: Mumbai Age: 36 Posts: 1,023 Member: 821646 Status: Offline Thanks Meter: 507	Most of the dislodged pads are NC. So not to worry about them. You should order UV Curable solder mask it helps in holding down the jumper wires in place. Next time try not to scrap the ground near the tracks. It really messes up and shorts the tracks while soldering jumperwire. I guess you can use the same Chip by reballing it. Most of the times the problem is not due to the Chip itself it is due to the broken pads underneith. Best of luck.

09-25-2018, 21:25	#8 (permalink)
christina_ Freak Poster Join Date: Jan 2010 Location: Canada Posts: 340 Member: 1211915 Status: Offline Sonork: 345634564 Thanks Meter: 93	I use 330 and i have done 20+

09-26-2018, 08:36	#10 (permalink)
CDMA_RASHID No Life Poster Join Date: Jul 2008 Location: Mumbai Age: 36 Posts: 1,023 Member: 821646 Status: Offline Thanks Meter: 507	What is the power consumption of the phone on DCPS. Try removing the Audio Chip. Lot of times the chip gets short. Or maybe pads underneith got shorted cause of miss alingment. If the phone was working before soldering back Audio chip. It is most probably case of it. Even if you over heat the board it would have no baseband but phone would not go dead. Hope that helps.

09-26-2018, 20:50	#12 (permalink)
CDMA_RASHID No Life Poster Join Date: Jul 2008 Location: Mumbai Age: 36 Posts: 1,023 Member: 821646 Status: Offline Thanks Meter: 507	Is that consumption after pressing power key or it is consuming that much after directly connecting to DCPS ?.