One quick but silent and deadly way to kill a linear amplifier is with bad coax. Coax can have a short, an open, be too small to handle the power, but a common and often unrecognized problem is bad soldering on the coax plug. Bad soldering can and will cause the opens and shorts mentioned above which are generally pretty easy to trace, but another common one that is often missed is too much solder on the tip. Yes, too much solder on the tip will make the tip bigger and fit tighter in the SO-239 socket, but that is temporarily. The too wide tip will expand the internal socket connectors out like in a V shape instead of a U shape. I think its easy to see that the V shape will have a lot less contact area than the U shape. Even worse, when you put a correctly soldered PL-259 connector into the now widened V shape socket, you will get very little connectivity if any at all. If your tips have too much solder or are bulging out, unsolder that extra solder, or replace the tip or the whole coax assembly. On the sockets, if it has widened out into that V shape, you can try to reform it using a pick, or replace the socket. It is best to test your coax cables and sockets once in a while before something bad happens. I check for continuity, shorts, loose wires, frays, and loose connections. Kinda like checking the oil of a car, rather be safe than sorry. Here is a link of the followup with the coax and SO-239 connectors repaired. • quick followup video o...