Some complaints about mobile phone charger design

　　Occasionally one comes across a simple, useful, functional device and happily tucks it into an already overloaded work bag until one day it breaks for unknown design reasons. In this case, I'm referring to a cheap USB power connector.

　　I got a couple of these connectors from Microchip a while ago. This simple cell phone backup battery is made by an unknown Chinese company with a Microchip logo on it. It's a good idea from a sales perspective. Ironically, however, there are no Microchip parts inside. The main device is from Texas Instruments, an LM324 op amp, plus a USB power detector and battery charging circuit.

　　I may need your help to identify the other components, but a large (relative to the size of the board) inductor and a 22.16V electrolytic capacitor tell me that U1 (labeled DKJ8) is probably the output transistor of a low frequency switching power supply circuit.

　　Either way, this is a classic example of a useful device being made badly: a poorly designed mini-USB input power connector that fell off when I needed it most. Now, the device is useless unless I re-solder it. The size of the soldering locations and their location under the connector make repair impossible. Repair suggestions are welcome. For now, this will be an interesting lesson for those who consider the MCU or processor to be the most important part of an advanced system. If the connector is broken, it is worthless to restore it!

　　How often do you encounter a good device or design that is rendered unusable due to stupid corner-cutting?