Test Leads Need Love Too.

Take some time to check over your test leads.

 Look for damaged insulation, insulator boots, and the most hideous of all, the intermittent connection to the alligator clip or banana plug.
 I don't do this as often as I should. And I am guilty of wasting a lot of time trying to figure out why something is not working , just to find my test lead has an intermittent or bad end on it.  

Many of the imported alligator clips leads with the thin wires are not soldered to the alligator clip but have a really poor crimp connection, leading to all sorts of aggravation. I have found mass intermittent problems with this type of cheap connection. I make it a rule to pull back the insulator boot on new leads and solder the lead to the clip. Man, some of those leads are SO thin.....  I have replaced a lot of thin wires, even on the new leads.

 Good quality banana plugs will use a hollow "bolt" that you solder the lead inside of, then it screws into the banana plug. IIRC,  Cinch Jones make these. They are great. Once in a while I check to make sure the "bolt" is tight.
 I have the best success with the banana plugs & jacks by Cinch Jones, Pomona, and the top end Philmore banana plugs & jacks. (Philmore has been around for close to 100 years now. Their top end products have always given me good service at a lesser cost than the top of the line brands. I have been using some of their banana plugs and jacks for over 42 years without a failure!).

Oh, and beware- Some banana plugs have a screw in the SIDE that screws in to hold the wire in place. The screw protrudes through a hole on the insulator of the banana plug, leading to a very rude shock. I avoid those like the plague!

Cheap banana plugs and alligator clips will quickly fail in use. Buy the better quality ones, even if they are a lot more expensive. They last decades, not a few months. Be sure to compare construction of banana plugs also. The best ones will have the pin down the inside center, and the contacts bowed outward. The really cheap ones don't use this construction, and lose spring tension after a very short time leading to great irritation when the lead wont stay in the socket properly.

I prefer silicon test lead to just standard wire. it will handle high voltages safely- Check the specs before buying it. I like 1KV rated in silicon wire., and many of the thin import wires just plain fail from poor quality wire, and voltage breakdown. You do not want to use wire rated for 50V on a test lead for old radios with voltages approaching 800-1KV.