Hi everybody!
One day I decided to reflash my charger. I downloaded an archive from this page: http://www.hobbyking.com/hobbyking/store/uploads/1019411227X1816993X33.zip
The archive contains DFU firmware and two firmware images: the original version 1.13 and a patched one, which does not require a balance connector. I chose the patched one.
I did it all as written in the manual: open the file, typed in VID 0x0000, PID 0x0001, click UPGRADE...
Briefly, I did it at work on a laptop with a bad USB port.
Well, it didn't go through. The laptop wouldn't detect it.
I've got a brick :(

I thought I'd reflash it at home, because the ports of my home PC were all right. But no such luck: the charger was dead... I tried to figure out what was wrong. There were no questions about the processor: MEGAWIN MA84G564 is a clone of 80С51, so I had no idea how to flash it...
I found a recipe of flashing it using DFU on some German website. It said that I had to ground Pin 5 of the ISP connector, which was not soldered in (on the board's top), and do the same for the RESET (Contact 3).
Here is a picture of the connector from the website:

After that the system should identify the processor. Although I knew Google was same old freak, it did figure out how to handle it properly. Here we are. No effect.
Stuck as before:

I found a datasheet for the processor. There was a 47k resistor drawn between P45 (OCD_SDA) and ground, and there I read: FOR DFU. This connector is P45 and there was the ISP connector. I found a resistor, put it between GND and OSD_SDA, tried to reset it with pincers (GND RESET), but it didn't work. Another glimpse into the datasheet, and there I saw +5v for the reset button. Then I shorted RESET to +5v and... The speakers boomed merrily: USB connection successful!
Then I opened DFU again, type in VID and PID, open the file, click upgrade, and there it was in 15 seconds:

After connecting power supply:

Well, the flashing was successful. I didn't check calibrations, I think they're all right.

Now a little sum-up:
Reflashing a bricked charger is no big issue:
1. Insert a resistor between GND and OCD_SDA (Contact 1 and 5 on top of the board) into the holes.
2. Short-circuit +5 and RESET (Contact 2 and 3).
3. Flash it.
Now I'm considering using this flashing technique in IMAX B6 mini featuring the same type of processor and contacts.

Well, for those living under a rock:
I have USBASP, Pickit3, STK500, TL866A, Turbo-6, BiDi Pro, Orange-2, ST-Link 2, and chances are I've missed something.
This is 80С51, not Atmega32 or Pic, etc.
Steal a look at the documentation for the processor and stop getting on my nerves!
This is the translated version. You can read the original Russian article here.