How to replace the internal buzzer with a bigger and more powerful one.
A magnetic tranducer buzzer will do that can handle 8 volts or so, I use 85db version, found on many motherboards are those rated 5.0v, but I've tested and it seems OK on the radio.
But this mod using a servo extension cable so if the buzzer gives up you can easy replace it.
I use a 7.0v buzzer in this radio.
(do note, there is higher voltage buzzers out there, but then the volume goes down, so overdriving one a bit will give higher sound)
Start with removing the battery.
Then remove the power button, and the two dials, they come loose by prying them out like in the picture.
Then remove the screws for the back plate, 5 of them.
Look at the picture below, remove the screws marked with Red arrows, and pull out the cable marked blue.
Pull loose the antenna wire
Use a long nose plier to get the antenna loose, you need to press the two plastic halves together while pulling the antenna out.
Now to the tricky part, Lift the board at the bottom of the radio, it will look like the picture below.
You need to loosen the LCD flat cable, it's done by taking a small screwdriver and "flip the hinges" for the locking mechanism. (shown in the right arrow in the picture below)
Also remove the red/black cable (left arrow at the picture), it's secured in the board as well, unhook it from that.
Here is a detailed picture, the brown part is the hinge, flip it with a small screwdriver at the end.
Now you can flip the whole motherboard so you can access the buzzer.
Pry the lid off the existing buzzer (there is small holes on the side, very easy to do), the result becomes like in the picture
below minus the cables I already soldered.
Now solder a Servo extension cable on to the pins that are located inside the original buzzer, NOTE THE +/-
in the picture below you can see my new buzzer.
The reason why to do it this way is that only way to unsolder the existing buzzer is to loosen the TX board, and that's soldered with 10+6 pins, so that's a real pain to get loose with a big risk into it.
Now it's "just" putting it back to together, for the flat cable from the LCD, make sure the hinges is open, and push the cable in, wiggle it a bit so it's fully seated, then close the hinges with a flat screwdriver.
Re-connect the two cables you took loose. (red/black close the LCD, and the Control stick cable.
Do note that the board in the picture below is loose (for the touch dial) and just should be seated in the correct place, so do not force any pressure down to get the mother board in place without checking this is seated in it's correct position.
Easiest is to wiggle everything down, it should not require any force.
Put back the antenna, Antenna wire, and all screws.
Note in the picture below (yellow arrow) where lead the servo extension cable out., make sure it do not get jammed somewhere.
After you get everything back together you can see in the picture below where the new buzzer is located (red arrow)
You need to drill a hole in the radio at this location
Do note that exact location depends a little on how big buzzer you use, so make sure you get it good for yours.
I secure the buzzer with using a thin double-sided tape which I cut like a square or a ring with hole in the middle, place it over the hole in the front cover and then, put back the back cover, screw back the 5 screws, then put back the power button and the dials.
All done.