Anyone else got their christmas tree and decorations up yet?

Just a few tidbits for those with busted LED strings.

I spent the better part of yesterday troubleshooting the lower third of my pre-lit LED tree. Hum tracers don't work with stupid LED's and they run cool, so thermal imaging doens't help either. I ended up pulling everything single bulb on the lower third of the tree and testing each bulb individually. A swiss army knife is a real life saver, use the blade to flick open the tab and then use the back of the blade as a wedge to pry the bulb out with the housing. Took about 45min to remove them all.

Set the multimeter to test for continuity, using the el cheapo power fist multimeter, the bulb lights up when touching red lead to side with locking tab and black lead to other LED prong. The red is connected to the regular plug (not the one for testing current) while the black is connected to the common. LED's are directional, so try flipping them around if it doesn't light up.

I poked around the pre-lit string a bit and saw that it's fairly simple, 2 strings with 2 plugs each in series, and a third section in parallel between the two strings. Start with the bulb socket closest to the wall plug, make sure there's 120V there. Put a bulb in, and move on to the next one in line and keep repeating until all bulbs are seated and the tree is nicely lit again.

Each C3 LED bulb is 2~3V, blue and green ones being 3V. So, for each bulb socket you test, just make sure it doesn't drop more than 3V from the previous. You'll need to be > 60V at the end of your string. I had about 15 dead bulbs all blue and green. This was a 4 year old tree with no major outage until now, so I'm fairly pleased. Reading other posts online, it's not uncommon to get 3 dead bulbs per week, eck.

It's a long and tedious process, but it sure beats random testing and at the end you're fairly certain that you'll end up with a working string of LED lights.