Short answer, they are definitely not worth it!!!!On all iPhones and iPads they have a charging IC that also handles all USB communications. Up until the iPhone 7 plus this chis has been called the Tristar. On the iPhone 8 and above it has been re christened Hydra. This charging circuit is designed to communicate with the usb charger plugged into the dock connector. The MFI certified charging cords have a circuit board in their ends that is designed to communicate with the charging circuit in the phone, it also protects against voltage spikes.The cheaply manufactured cords sometimes do not have the circuitry designed properly it at all and this causes the charging IC, Tristar and Hydra to get electrically damaged causing the device to fail to charge the phone or power on at all.
Some common symptoms of a failed charging IC are:
- Slow charging
- Charges only to 6%
- Battery reports a false charge.
- Wont recognize charging cable
- Wont detect on itunes
- Wont charge battery from dead
- Device stuck in a apple logo boot loop
In the video below I demonstrate the diagnosis and repair of a failed Tristar chip on an iPhone SE.This was a challenging job due to the presence of hidden underfill under the chip.