Iphone 4S no power on, short somewhere - GSM-Forum

smiler25 · 09-30-2014, 16:26

Bit of background: a few months ago I used a bad charger and the power protection circuit broke, so I could only charge the phone when off, and couldn't sync it. Getting a new phone so thought I attempt a repair and would sync it one last time so I could get all my data off etc.

Tried to jumper L3 & L4, but something has gone wrong and now I can't power on. The power management unit (I think) gets very hot when battery is plugged in. Not so bad with USB but still can't turn on.

Do I need to replace the chip? Can't find anywhere that has the exact same symptoms. Thanks!

smiler25 · 09-30-2014, 17:39

Bit of background: a few months ago I used a bad charger and the power protection circuit broke, so I could only charge the phone when off, and couldn't sync it. Getting a new phone so thought I attempt a repair and would sync it one last time so I could get all my data off etc.

Tried to jumper L3 & L4, but something has gone wrong and now I can't see the LCD. The power management unit (I think) gets very hot under some situations.

I thought it wasn't powering on but by using the vibrating switch I realised it is on, I just can't see anything. All I need is to sync it one last time, not too worried about getting the screen back. Thanks!

dog68 · 09-30-2014, 19:49

Have you got a microscope? have a look at the lcd connector, see if any of the filters are missing, also check the capacitors for a short, and check L18/L19, D4.

smiler25 · 09-30-2014, 20:00

L18/L19 seem fine, can't see contacts on D1 to check?

09-30-2014, 16:26	#1 (permalink)
smiler25 Junior Member Join Date: Sep 2014 Posts: 4 Member: 2266429 Status: Offline Thanks Meter: 1	Iphone 4S no power on, short somewhere Bit of background: a few months ago I used a bad charger and the power protection circuit broke, so I could only charge the phone when off, and couldn't sync it. Getting a new phone so thought I attempt a repair and would sync it one last time so I could get all my data off etc. Tried to jumper L3 & L4, but something has gone wrong and now I can't power on. The power management unit (I think) gets very hot when battery is plugged in. Not so bad with USB but still can't turn on. Do I need to replace the chip? Can't find anywhere that has the exact same symptoms. Thanks!

09-30-2014, 17:39	#2 (permalink)
smiler25 Junior Member Join Date: Sep 2014 Posts: 4 Member: 2266429 Status: Offline Thanks Meter: 1	iPhone 4S no sync, no LCD Bit of background: a few months ago I used a bad charger and the power protection circuit broke, so I could only charge the phone when off, and couldn't sync it. Getting a new phone so thought I attempt a repair and would sync it one last time so I could get all my data off etc. Tried to jumper L3 & L4, but something has gone wrong and now I can't see the LCD. The power management unit (I think) gets very hot under some situations. I thought it wasn't powering on but by using the vibrating switch I realised it is on, I just can't see anything. All I need is to sync it one last time, not too worried about getting the screen back. Thanks!

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09-30-2014, 19:49	#3 (permalink)
dog68 No Life Poster Join Date: Mar 2012 Location: cambridgeshire, England Age: 55 Posts: 760 Member: 1728699 Status: Offline Thanks Meter: 212	Have you got a microscope? have a look at the lcd connector, see if any of the filters are missing, also check the capacitors for a short, and check L18/L19, D4.

09-30-2014, 20:00	#4 (permalink)
smiler25 Junior Member Join Date: Sep 2014 Posts: 4 Member: 2266429 Status: Offline Thanks Meter: 1	L18/L19 seem fine, can't see contacts on D1 to check?