Did you check the fuses in the plugs?

check each globe to make sure none are loose, sometimes a loose globe that isnt contacting properly can break the circuit, and then check to see if you can see any that may have burnt out. They won't all be faulty, but you need to find the one that isn't working.

I would throw the whole bunch out. You can get them so cheap these days.

I should have said start at the first none working globe but it doesn't hurt to check all the globes for loose ones if there aren't too many and if you cant find any loose ones, try replacing the first non working globe

you know what, forget my second post, I'm trying to remember this from when I was a kid (it was my job to find the loose or faulty globe when the tree lights wouldnt work), but I'm pretty sure I was right the first time, it could be any of the none working ones, dang my memory is not what it used to be!

Most sets these days don't require all the lights to work.

I had that problem - my old wiring was causing surges that lew the fuse in the lights - there are usually 2 for longer strands. You can replace the fuse if you still have the ones that came with the set -o r just replace them. However if it has happened to that many you might want to have the outlet checked.

Many strands arE made so that if you have a lose bulb (not a burned out one) part (normally half) will go out verses the whole thing. Start at the first out bulb and press to tighten. When you find the right one the string will light.

If this does not work, wrap the string around your neck and pull.....oh wait, maybe it's only me who hates those freaking lights (but would never have a tree without them lol).

Save yourself now.....
If you think that the right color to paint was difficult you haven't seen nothing yet.
Step away from the lights.
Go buy new.
Remember on Dec.26 to hit Target and get new ones for next year !
God help those people with pre-lit trees.

No home should be without a Lightkeeper Pro...it has saved us from tossing out many strands. DH swears by it.

Here is a link that might be useful: Lightkeeper Pro

i had the same thing this year!!! and i thought the sets that only half lit(4-5) were pretty new too! and, i KNOW they were all working last year! i just couldn't spend the time trying to figure out why...replaced the fuses on 2 sets-nothing...jiggled a few bulbs and decided my sanity was worth the few bucks to replace them!! ruthlessly threw them AWAY!!!

I threw away 6 strands this year for that very same reason. Then went and replaced them all for less than $15.00. That was easier than trying to wiggle and adjust every dang bulb. Putting up the lights is my least favorite chore, and no one else will do it, either. Busybee3 and are on the same page with this one.

We cut the lights off the tree at the end of the year before putting it on the curb. It's easier just to buy 1200 new lights the next year.

Here's another vote for the Lightkeeper Pro. I just received mine recently and it's just amazing. It instantly lit two strings that were completely out, and fixed others that were partially lit. This little tool will not only save you the aggravation and time involved in either replacing strings or endlessly testing bulbs, but will save money as well.

yes it is an evil,evil plot.I always plug them in to check them first. And we decorate at night while they are on- it's more festive that way.
My lights like to wait until they are on the shrubbery- and then poof! half go out. or sometimes they are tricksey and wait until the next night. arrgh.

We had a lightkeeper pro last year- bought and returned for a full refund. POC.

I threw out 3 strands of last years new outdoor bulbs because they would not light.

OK, who jinxed me!

After checking the lights to make sure they worked (two lights were out, but the rest worked fine) I just carefully wrapped a long string around my front door garland. About 24' worth! Now, only half are coming on (and it's not the half that had two lights out.)

Suggestions? I did a quick check using some of the tips already written here. I will check the fuse tomorrow when it is warmer out, and do a thorough check of the sockets.