We had an iphone 7 plus in recently after our customer had cleaned the phone after water damage and the phone would still not turn on. The water damage was minor and had only affected the top of the board.
Upon inspection we had a 5 amp short on VDD main. We checked over the board and found that capacitors C2609-2611, where all very corroded and needed replacing. We removed these components and tested again, unfortunately the short was still present. We then removed the CPU shield to inspect this area. The shield had not been removed so cleaning of the board could not have been done properly, after removing the shield we found a lot of corrosion above the CPU covering capacitors and resistors. We cleaned the board and saw that there were still several components that were visibly corroded, most seemed minor and we did not think these were a problem. We probed around in diode mode and found one nasty looking capacitor C3325 on the speaker amp line that was short. We removed this capacitor which cleared the short on this line and on the VDD line too, these lines where linked through U3301
We plugged the phone into our power supply and it booted up normally, we tested the basic functions and all seemed fine. We then cleaned the board and reassembled the device and returned it back to our customer who was very happy to return the device to its owner fully working.
We love working on water damaged devices as the owners are always so happy to get their phone and more importantly their data back!
If you have a water damaged device with important photos on please feel free to get in touch. We love a challenge!
We recently received an iphone 7 that would not turn on.
We plugged it in to charge and got no response from the phone. We then cleaned out the charging port which made no difference.
We then cracked it open and connected up to our DC power supply, it turned on and seemed to work perfectly other than charging. We tested with a new battery and charging port which made no difference. We then tested what voltage we get through the battery connector when charging and we got a very low reading of 0.45v.
In the iphone 7 the common causes for not charging are the tristar (charging ic) and tigris (USB ic). Unfortunately on the iphone 7 when one of these IC’s goes bad it usually damages the other, this means when replacing one we will replace both for peace of mind, otherwise you may find your device suffering from the same fault in the near future.
We believe that if your going to do a job you should do it right, this is why we do repairs our own tried and tested way and if we can find a way to improve a repair, we will do so.
So we disassembled this iphone 7 and tested the charging circuit. Of Course we found low voltages on the 1v8 and 3v lines coming out of the tristar. We replaced both IC’s and this brought the voltages up to where they should be. We then cleaned the board and reassembled for testing. The phone now pulls around 1A through the charger which is perfect and is charging nicely. We are also getting 3.72v through the battery connector which is a very good reading.
The phone was then returned to the customer who was very happy to get their device back and working within a day.
If your having issues with an iphone not turning on or charging please feel free to get in touch.