Baofeng UV-3R+ Charger Base Repair

My Baofeng UV-3R+ Dual Band UHF/VHF Transceiver has served me well during the year of ownership. 
I use mainly the 2M band fucntion in order to communiate with other Amatuer Radio Enthusiests on a local repeater. 

One day I went to charge my UV-3R+ and noticed that the LED (Light Emitting Diode) on the Charger Base did not rapidily flash between red and green when plugged in. The LED on the Charger Base was off yet the LED on the AC Adapter was lit. In addition, the LED on the Charger Base did not change to a solid red indicating that the UV-3R+ installed was charging.   

This led me to believe the issue was with the Charger Base itself.

Step 1 Disassembly

The bottom of the UV-3R+ Charger Base just snaps in place with the top. All you need to do is take a Jewel's screwdriver and pry where the two halves meet to separate. Do not be fooled by the screw heads on the Charger Base bottom, they are molded in the plastic and serve no purpose.  

The next step is to remove the screw that holds the Charger Base printed circuit board in place. See area circled in the picture below.

What puzzles me is the center terminal, circled below, does not have any internal connection. Yet, there is a mating contact on the back of the UV-3R+ battery.  Looking on the Internet I have found references of the a "third pin" used to monitor the internal temperature of a Lithium ION battery or to balance a charge between cells. There is the letter "T" over the center contact of the UV-3R+ battery, making me believe this was for a temperature sensor. It is a mystery why this function was never implemented. 

Step 2 Diagnosing the problem

I could measure 5 Volts with my Multimeter on the coax male connector that plugs into the Charger Base. It was a mystery why the Charger Base was not being powered.  Upon further investigation, I determine that the coax female connector, soldered to the Charger Base printed circuit board, was the culplit.  I removed the coax female connector from the Charger Base printed circuit board in order to take a closer look at it. 

I immediatley determined the issue once I looked down the barrel of the coax female connector. The center pin had broken free and was pushed back in the connector. This prevented it from making contact with the center contact of the coax male connector.  See below picture.

Step 3 Fixing the Problem

The lead that holds the center pin of the female coax connector was very flimsy. I soldered a much thinker terminal pin to it. This will give it added physical strength that will prevent it from being pushed back into the connector in the future. 

I had to drill an extra hole in the printed circuit board in order to accommodate the supporting thicker terminal pin.  You can see the end of the terminal pin protruding from the printed circuit board, circled below. This is before I cut the terminal pin flush with the printed circuit board.

Step 5 Reassembly

Putting the charger back together is just the opposite of taking it apart. The printed circuit board is attached to the top section of the Charger Base with a single screw (circled below). The bottom of the Charger Base just snaps in place with the top.

Step 6 Testing

Testing is pretty straight forward, plug the AC Adapter into the wall and connect the AC Adapter cable to the Charger Base. The LED on the Charger Base should rapidly flash between red and green. See area circled in the picture below.

Install the UV-3R+ into the Charger Base, the LED should change to a constant red when charging. The Charge Base LED will change to a constant green once the UV-3R+ is fully charged. ​

The LED on the AC Adapter is green when:
- It is not connected to the Charger Base
- It is connected to the Charger Base and without the UV-3R+ installed.
- It is connected to the Charger Base with the UV-3R+ installed and fully charged.

The LED on the AC Adapter is red when the UV-3R+ is installed on the Charger Base and it is charging.

Conclusion

Repairing a UV-3R+ Charger Base is a pretty simple task, requiring a minimum of tools. I recommend disassembling a broken UV-3R+  Charger Base, determine the root failure, and fixing it, before purchasing a new one.