I have an old (installed 1989) Merlin 2500N garage door opener. The remotes (they look like this) only work if I operate them right by the aerial (basically touching). I have run a 10m extension aerial wire that hangs outside so the door can be operated from outside!! However, I would like to fix this. I don't really want to spend even $35 on a new one (TradeMe) only to find it doesn't work. My question is - is there any way of testing what the issue is. (i.e. is it something to so with the receiver in the opener unit?). I should note that it is not a battery issue. Thanks.