Thanks for the reply, bclaire! I am in sunny California, USA. I'll send them an email as well in the hopes they can provide some direction.

Hello All, This is my first post here. I have a VT-1000 Valve Tester. It's been great as a simple way for a layman to test and "match" tubes, but recently it has stopped working. When I put a tube in, select the type, then start the test it looks like it is working for a while, then fails the tube. ...