Assuming that you have already changed the batteries, this problem is normally caused by the printed circuit board being dirty inside.
First, remove the LED / transmitter cover by sliding it off the front ofthe R/C. You will have to very carefully drill out a rivet under the battery compartment cover which also holds both parts together. To open it up CAREFULLY prise the case open down the centre.
Once inside use cotton wool buds soaked in alcohol to clean the PCB and the rubber pad.
Reassemble and it should work wonders.
JP, December 2008
