[Yaesu] FT-411 Intermittent

[W0rw@aol.com]

Any body ever see an intermittent Walkie Talkie  FT-411,
or maybe FT-211/FT-311 that has intermittent power output.
The Red transmit LED won't come on until you give the unit a sharp tap...
Also fails at cold temperature.
Acts like a broken wire going to the transmitter power amp.
The driver always works. Receiver works fine...
Any one know what might  cause this ? 
i opened the unit up and didn't see anything loose. i have not started to 
remove the RF shields yet. Its not the battery.
Thanks
Paul  w0rw