How to repair your Imax B6 charger screen

Quite a while ago I bought a second hand Blade 130X helicopter, which came with an Imax B6 charger included in the deal. The charger always performed flawlessly, but the previous owner damaged the screen on it, and only half of it was working.

My Imax B6 charger. you can see the display acting up on the right side.

At the beginning I could not be bothered by it and just used it as is: I was missing the total mAh I was putting back in the batteries, but that was it.

A couple of weeks ago I decided that enough was enough and that I had to repair it. To my surprise the operation is fairly simple and completely inexpensive, so I decided to make a quick tutorial on the website for you to try and do the same should you be in the same position.

As a note, this operation works with every Imax and most of the Turnigy chargers on the market, because they all use the same display.

What you need to perform this operation is:

• Phillips screwdriver
• Soldering iron
• Pliers and cutter
• Replacement display. It is a 1602 16x2 LCD Display, model HD44780. I bought it on eBay for about a couple of dollars.

DISCLAIMER: Before you start, beware that this operation requires you to disassemble and solder electronics components. I cannot be held responsible should you get injured or damage your charger.

Without further ado, let's dive in!

Disassembly

These charger are dead easy to take apart: 4 Phillips screws on each side of the main body allow you to disassemble the two side plates. You will notice that the main body is an aluminium extrusion which holds the electronics board within its internal profile. Ingenious!

Circled in red the four screws which allow you to take the two side plates apart and access the electronics board

Once you have removed the side plates you can wiggle carefully the board out of the main body.
Please be careful doing so because the four buttons protrude through the case, so you need to push them down while you slide the board out. Once you do that, you will be left with the board

This is the electronics board of the Imax B6, with the malfunctioning screen

Desoldering Destroying the old display

Yes, I tried to do a clean job and desolder the old LCD out of its place. Well, I could not; The thing is pretty stuck down and no matter how much heat I would throw at it, there are too many pins (16) to desolder to be able to remove it.
So on I went with option 2: cut the pins, remove the LCD, solder a new set of pins and move on.

All the 16 pins have been cut out, because of the impossibility of desoldering the LCD out of its place

 Once the pins were re soldered to the main board, things get really easy: just slide the new LCD into place and solder each pin to the corresponding pad to the screen, like so:

The new display is back in place, all is ready to be reassembled and tested

Next and final step is, obviously, to slide the board back in the case, again paying attention to the four buttons and hook it up to a power source to test your work.

For reference, please find the schematics of this charger: accidentally I damaged the traces on the board and had to rewire some connections between the CPU and the pins. I used this pictures I found on rcgroups, so I thought that you might find this useful as well.

Stay charged!

The schematics for the Imax B6