Sorry to hear that you are having some problems with your X-70. My first question would be whether you are having problems with the internal speaker, or just your headphones? If the speaker works fine, then the problem might be with the headphones themselves. Especially since you already sent the detector in once, and it was returned to you. The second question would be whether you have tried these headphones on another Minelab detector? The reason I ask if you've tried them on another Minelab detector is because many headphones have a "stereo / mono" switch. For example, my White's detectors require the switch to be in the opposite position as my Minelabs. If you haven't checked to make sure that your headphones are compatible, or if the toggle switch is in the correct position (if yours has a toggle switch), it would be worth checking before you send the detector in again.
I hope you don't have to send it in again. But if you do, and you live in the US, don't ask for Bill Schultz. The Customer Service Manager's name is Dick Shultz. And he does an excellent job for Minelab USA.
With a velcro embedded, one-piece strap, I don't understand how your wrist strap can fall off, if it is installed correctly. The X-Terra strap is a one-piece strap whose two ends are much different from each other. One end looks like the letter T, when viewed from the edge. And the other end looks to be simply folded over and sewn together. The end that has been sewn should be inserted through the slot from the outside of one side of the armcup. This will allow the end that resembles the letter T to pull up snug against the slot. The shape and size of that end (resembling the letter T) will not allow it to pass through the slot in the armrest. Pulling on the end that looks like it has been folded over and sewn, run the rest of the strap straight across through the slot on the other side of the armcup. After going through that second slot, (from the inside - out) pull all the slack through that second slot. The remainder of the strap should now be folded back over the top of the armcup (above the slot) and the velcro on the bottom side of that portion of the strap will attach firmly to the top part of the strap running between the two slots. If you put the strap in upside-down, the velcro will be in the wrong position to "lock" to itself. That is the only way I can imagine the strap "falling off".
Minelab Electronics was formed in 1989. In 2005, Minelab acquired Parketronics, an electronic component manufacturing company. Minelab's growth rate from 2005 to 2007 was 28%. At the end of 2007, Minelab had a 30% market share. Both of these facts led various companies wanting to make Minelab part of their holdings. Codan Limited paid $70,500,000.00 for Minelab (and Parketronics) in February 2008. "Minelab adds the growing global consumer leisure market to the markets Codan currently serves, and also brings relative strength in global military markets for landmine detection - a particular strength that Codan will leverage as it enters military markets for its HF (high frequency) radio products," Codan chief executive Mike Heard said. "Aid and humanitarian customers across many countries require both communications and mine detection equipment."
HH Randy