RE: need radio/servo help.
I have no idea how much experience you have so I am going to ask,
What radio gear are you using? if you have to replace the receiver it might be cheaper in the long run to go for CEN's radio swap program.
Is the battery fully charged or if you are using alkalines are they any good? If they are good try plugging the pack directly into the receiver do not plug it into the on/off switch.
Did the receiver get wet or possibly damaged somehow?
rolland