RE: Radio hit or short ?
Somewhere in these posts there's one about using an engraver, with a 1" chunk of fuel line hose on the tip, to excite the Rx, switch, connections, etc. Just turn on the engraver, and put the fuel line / exciter tip on the Rx case or switch case or servo, or whaterver. That imparts some fairly random vibration to the component, and you can work the transmitter with your other hand while you're doing it.
I'm gonna do that, one of these days. I have... er... a receiver that survived a crash. Yeah, one receiver, that's it.
Good luck,
Dave Olson