If i read this it seems to be an antenna issue.
2,4 GHz is quite sensitive if there is something wrong with the receiver or transmitter antenna.
The coaxcable must be stripped at the end for 31mm (that is the due to the wavelenght).
If the cable is damaged or nodded it most of the time doesnt work anymore.
So check it and if you are not shure (or technical) bring it to a store.
GJ