[Amps] Alpha 9500 goes weird when grounding the Key In line

[Jim Smith]

Got a K3 driving the amp.

After transmitting for a few seconds The Oper light goes out and the 
Stby light comes on and whoever I'm talking to starts saying, "Agn  Agn."

Same thing happens with 0.0W of drive from K3

Same thing happens when I disconnect the Key In line from the K3 and 
simply short the line.

Any ideas of how to fix this?

73, Jim	VE7FO