Fifth generation of iPhone. Repair of this device is straightforward, and requires screwdrivers, prying tools, and patience. GSM/CDMA / 16, 32, or 64 GB / Black or White.

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Logic Board Dead - Possibly Fried After Water Damage

Hello.

I'm 14 and have been repairing iPhones for just over a year now. My cousin was on holiday just before christmas in the Caribbean. She bought a waterproof case from Apple and was taking photos In the sea. I'd seen previous results and they were very good. However, on the last day the case let sea water in. She contacted me when she was home, I told her not to try and switch it on or to charge it, but she had done both on holiday in panic. Apple have confirmed they will replace the phone but there are many valued photos etc on the phone. Taking it apart, corrosion near the bottom was bad. Removing the battery removed one of the four pins for the battery connector. I scrubbed the board clean with a toothbrush and IPA. It's cleaned up well, and looks normal apart from the battery connector. Earlier today I removed the 3 removable logic board shields and searched for damage. I can't see any burn marks etc? got a new dock and screen and tried to power up the device using a charger without the phones battery, but the phone remained dead. It didn't connect with iTunes but I don't know if re assembling the phone to put it into dfu mode would make iTunes recognise it? I'm waiting for my dad to get me some more IPA and I will soak the logic board in an ultrasonic bath. Can anyone help me, any advice to why it won't come on? is it completely dead?

Thanks in advance, Sam.

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Power issues are not fixed by blindly trying, but testing.

Which pin of the connector did you remove?

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With the logic board sitting the right way up, as if it was in the phone, it's the top pin. I know this is important but I thought I could still get power into the phone?

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Chosen Solution

Sam--my advice is to send the board out for battery connector repair--it's about $20-30 on eBay and very straightforward if you have experience.

You will certainly fail, like we all did, the first time you try it. This phone has a high likelihood of having salvageable data, so you might not want it to be your test case.

If you insist, the battery connector repair is done under the microscope with flux and a soldering iron. Hot air will melt the connector. There are all sorts of tips that you learn just from experience--in the first me I did, I couldn't understand why pad #1 and #4 (+ and Gand) were like mud, while solder flowed fine on the other pads. I assumed it just needed more heat, and ended up knocking off tiny components that I had to replace later--and didn't have the equipment or skills to do that either. Fast forward a few months, and now the job takes about ten minutes tops.

Good luck

Jessa

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Thanks for your advice. Going to attempt this repair myself as I need to start somewhere! My dad has a lot of experience soldering and creating pcb that are as compact as the iPhones logic board. I'll make sure to post my results! Thanks again

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Hello.

I have attempted the repair. new battery connector is soldered down but the phone is stuck at the apple logo, before shutting down and switching on again, in a loop. How do i fix this? thanks

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that is a typical symptom of a failed battery connector repair--check for continuity across the pos and neg battery pins (the far left and far right). you should not hear a beep. Check between the gnd pin and gnd (any part of the shield) you should hear a beep. Check between the pos pin (closest to the main part of the board) and the copper dots nearest that pin--you should hear the continuity beep there.

If you have access to a direct current power supply, connect a lead directly to the pos and neg battery pins on the board and see if the phone will turn on as normal.

There are other ways to get stuck in a boot loop, but in this case, failed battery connector repair is most likely.

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Most Helpful Answer

The top pin is BATT VCC, it supplies electrical power for the entire phone. Cell phone logic boards are usually designed to be only powered on with functioning batteries attached. Simply plugging the charger in would not work

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What do I need to do to get the phone to work then? just replace the battery connector?

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Of course you should try this first

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can you give me any advice on doing this? never done this before. What equipment should I use? soldering iron or hot air rework station??

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This is probably too hard for you now. Hot air rework station should work but it is really easy to mess things up. If you decide to do the repair yourself, you should practice on some junk boards first, to learn wow to use the tool properly without causing addictional damage or injury. Iphone boards are very compact and difficult to work on, so more practice than other usual repairs are needed.

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What other tools do I need? A flux pen? do I need any type of tape for heat protection?

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Sam Murphy will be eternally grateful.
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