Went to fly my 2 year old H9 UltraStick-60 set up with quad flaps this past Friday. The right flap was not responding. I almost decided to fly anyway. After a bit of fiddling though, I noticed that the (Hobbico) volt-watch was "pegged in the red", indicating low voltage (on a freshly charged battery). Once I disconnected the flap from the servo extension the voltage-watch was back in the green. Apparently somewhere in the circuit from the receiver to the servo there was a dead short. If I had taken off it would have been a very short, expensive flight!

The beauty of this device is that it shows, with a series of L.E.D.'s the voltage level of your battery pack under actual load, as opposed to the simulated load that external voltage checkers provide. In this case, the symptoms indicated a dead short somewhere, but I've also used this device to isolate binding servos, as the L.E.D. display is sensitive enough to display voltage drops as servos are exercised. Not bad for $10 device!

BTW, you probably all figured out that when I went to test the setup again at home, everything worked properly, no short to be found. Servo and related extensions will not be flown again, however.