Iphone 7 doesn't switch on and no power - GSM-Forum

worldwideunlock · 12-22-2019, 11:04

Hello,

I have an iphone 7 here that was dropped, cracked screen but not bad, just a few cracks.

I try to fix it.
Phone doesn't switch, no power.
Changed the lcd, battery, usb flex, no sign of life.
When plug the usb and run 3utools phone can be switched to DFU mode.
When trying to restore it can't swich to recovery mode and fails at 11%.
Probe in hands and checking for short at c1823, but it is not shorted.
Just thinking if that could be the tristar failure, but phone is detected in DFU mode, so doubt it could be the reason.

I checked other capacitors in that place where the c1823 is on the right hand side and some of them are shorted.

Do You think that this still could be caused by sdram/cpu ?
I've seen some movies showing how to fix the sdram but it is really complex and beyond my skills.

I bought this phone for just over 54 quid hoping that it could be fixed.

Can someone help me with that?
Please

phryne · 02-19-2020, 08:48

The problem may be caused by a software crash or a complicated hardware issue. For hardware solution you can check this guide here.
Fix iPhone 7 Won’t Turn On – CPU Repair

NajeebAslam · 04-05-2020, 19:01

reheat cpu may be it will help you

unlok_up · 04-21-2020, 14:42

Unlock your phone IMEI number.

fozzo · 04-21-2020, 17:20

Quote:

Originally Posted by NajeebAslam

reheat cpu may be it will help you

That’s the dumbest answer ever. Cpu has plenty underfill and rehot or reflow will end up in a shorted cpu, two or more balls will surely melt together.

kunal124 · 05-27-2020, 07:36

Quote:

Originally Posted by worldwideunlock

Hello,

I have an iphone 7 here that was dropped, cracked screen but not bad, just a few cracks.

I try to fix it.
Phone doesn't switch, no power.
Changed the lcd, battery, usb flex, no sign of life.
When plug the usb and run 3utools phone can be switched to DFU mode.
When trying to restore it can't swich to recovery mode and fails at 11%.
Probe in hands and checking for short at c1823, but it is not shorted.
Just thinking if that could be the tristar failure, but phone is detected in DFU mode, so doubt it could be the reason.

I checked other capacitors in that place where the c1823 is on the right hand side and some of them are shorted.

Do You think that this still could be caused by sdram/cpu ?
I've seen some movies showing how to fix the sdram but it is really complex and beyond my skills.

I bought this phone for just over 54 quid hoping that it could be fixed.

Can someone help me with that?
Please

hello

change tristar and check it will solve for sure

Nikolay33 · 06-04-2020, 12:13

Check the voltage of Nand.
1.8v and 3.0v. good luck

Smartparts · 06-06-2020, 19:54

Take off the board and reheat power IC

12-22-2019, 11:04	#1 (permalink)
worldwideunlock Freak Poster Join Date: Feb 2011 Location: Northern Ireland Posts: 407 Member: 1514899 Status: Offline Thanks Meter: 49	Iphone 7 doesn't switch on and no power Hello, I have an iphone 7 here that was dropped, cracked screen but not bad, just a few cracks. I try to fix it. Phone doesn't switch, no power. Changed the lcd, battery, usb flex, no sign of life. When plug the usb and run 3utools phone can be switched to DFU mode. When trying to restore it can't swich to recovery mode and fails at 11%. Probe in hands and checking for short at c1823, but it is not shorted. Just thinking if that could be the tristar failure, but phone is detected in DFU mode, so doubt it could be the reason. I checked other capacitors in that place where the c1823 is on the right hand side and some of them are shorted. Do You think that this still could be caused by sdram/cpu ? I've seen some movies showing how to fix the sdram but it is really complex and beyond my skills. I bought this phone for just over 54 quid hoping that it could be fixed. Can someone help me with that? Please

02-19-2020, 08:48	#2 (permalink)
phryne Freak Poster Join Date: Jun 2017 Location: USA Posts: 207 Member: 2730637 Status: Offline Thanks Meter: 101	The problem may be caused by a software crash or a complicated hardware issue. For hardware solution you can check this guide here. Fix iPhone 7 Won’t Turn On – CPU Repair

04-05-2020, 19:01	#3 (permalink)
NajeebAslam Junior Member Join Date: Feb 2020 Location: Switzerland Posts: 11 Member: 2947355 Status: Offline Thanks Meter: 4	reheat cpu may be it will help you

04-21-2020, 14:42	#4 (permalink)
unlok_up Insane Poster Join Date: Mar 2020 Location: Unlock World Posts: 94 Member: 2950243 Status: Offline Sonork: NA Thanks Meter: 1	Unlock your phone IMEI number.

06-04-2020, 12:13	#7 (permalink)
Nikolay33 Junior Member Join Date: May 2019 Location: Bulgaria Posts: 4 Member: 2910059 Status: Offline Thanks Meter: 0	Check the voltage of Nand. 1.8v and 3.0v. good luck

06-06-2020, 19:54	#8 (permalink)
Smartparts Junior Member Join Date: Jun 2020 Location: Vilnius Posts: 12 Member: 2959127 Status: Offline Thanks Meter: 1	Take off the board and reheat power IC