I think these use the same board as most of the galaxy radios, here is a link to the mod for the 55 with EPT360014B or EPT360014C board, I would check the board number to be sure, I have also seen d80 cut to give talkback in other galaxy radios.
I also have a galaxy melaka and was wondering how to add talk back on to it. Have you tried what the link said to do? If so how did it work?
Also have you done any other mods to your melaka?
Sorry guys I should have checked further before I posted, I found out that the melaka is made by ranger (rci), If you get the number off of the board we may be able to find something that way.
I sent a message to galaxy support and this is their response.
The name Galaxy is well known in the communications industry and many people will attach that name to something in hopes of boosting sales. All of our Galaxy Radios will have the letters "DX" in the model numbers as you can see on this website http://www.cbtricks.com/radios/galaxy/index.htm. The manufacturer of your radio is Ranger Communications Inc. (RCI) and they do not offer any support on your model. We only service and support the Galaxy "DX" Radio models which means we do not have any service or support available for your model.
I was unaware that Galaxy did not produce the Melaka. I swear that I saw it on there web site like 6 years ago. Do any of you know where I can find a manual and a schematic for the Melaka? I can't seem to find any. Also did unsoldering the one end of D80 work for you?