Chosen Solution
I have my friends iPhone 5 that is not recognizing it is plugged in to power. Also itunes is not recognizing it on the computer. He recently replaced the battery (not from ifixit probably ebay). Can the battery itself cause the phone NOT to recognize that the phone is plugged in? When I hit the power button, the flashing red battery is there with a lightning cord symbol on the bottom. Normally, when you plug it into a power source, the lightning symbol goes away and it just shows the battery. In this case, when plugged into a power source the lightning symbol is still there as if it doesn’t recognize that it is plugged in. I used a wooden toothpick to pick out some lint in the port, and still nothing. A few things I did was try using multiple known good OEM lightning charger cords and still no dice. I opened up the phone and disconnected, and reconnected the battery cable but no luck either. Can a crappy battery cause the phone not to recognize the cord? OR is there a deeper issue here? Thanks!
@hoshi, like aqi said, first you must check that your charging dock is clean, not corroded. Next step is to try a known good one instead. No need to replace it at this point, just overlay it the existing one and plug it instead of the old one and test with a known good cable and charger - or computer. If the phone still doesn’t connect via USB, you probably have a bad U2 chip. It is a controller chip responsible for USB communication and charging. It is a very common failure on iPhone 5. If you want to be “extra sure,” you can examine around the battery and dock connector to see if you see anything missing or damaged. Your friend could also have shorted something when disconnecting the old battery, if using a screwdriver for example to lift the battery connector. That would hardly be visible to the naked eye though. You can also try installing a known good battery (not necessarily new) that is already holding a charge. If it depletes quickly and/or phone produces heat between the CPU and SIM card tray and/or still doesn’t communicate with your computer and/or won’t charge anymore once empty then for sure you have a defective U2 (google it) that requires micro soldering skills and tools to repair. Definitely not a DIY repair.
If you have cleaned the charging port- and still no luck than you have to change charging port full flex cable- You can buy it on eBay
My guess is that he probably accidentally unplugged the charging port connector from the logic board. Its immediately next to the battery’s connector, I’d recommend opening it back up, unplugging the battery, unplugging the charge port connector, and then plugging them back in again starting with the charge port.
