Control/Dimming Led Christmas lights suddenly dim

[Morte615]

I have a bunch of strings of led Christmas lights that were working and suddenly are very dim. I checked the voltage at the end of the line and it's suddenly 2 volts! Normally I just throw the string away and replace it but I am trying to figure out what is causing this. Is it something to do with the rectifier (the nub on the cord usually near, the plug) or something else entirely

 

[JD]

Bet if you put a load on it, it goes to 0 and the lights go out. Many of the Christmas strands are a long string of LEDs in series. These are then fed from a resistor and a diode. Most of the time, all that stuff is fine. what goes bad are the lousy connections in the sockets, or crappy crimp jobs. Look at the cost of those strings, back out the mark-up and the parts & profit and you have a labor budget of 50 cents.