Turned out to be that it was just a happy coincidence.
The connection to the barrel connector in the end of the tester itself was the problem. I tightened the internal locknut on the connector and the tester is now working properly again.
I don't know why DarkStar stopped making this neat little tester.
It's perfect for quick and dirty verification of live, open, shorted or 75 Ohm terminated CATV lines. It can also determine if the cable is connected to the output side of a splitter.
Anyway, I'm just thankful that it is working again.
