My TNC is an old original...It has been dropped, flung across the room when hit by a prop blade, soaked with gas when my test stand tank sprung a leak, and otherwise abused..It's like an old Timex watch, takes a licking and keeps on ticking..I replaced the original on and off switch with a pushbutton...I always forgot to turn it off and ran the battery down....
The case is now held together with clear strapping tape, the screw heads went through the back cover...It still works great....