Pre-lit Christmas tree
 

Does anyone know of someone who can check out my 7ft pre-lit tree that won't light up? It's only 3 yrs old.

If this has a power supply have that checked out, I just had to order one for another tree that would not work. In this case there was a set of wires that shorted out and caused the power supply to fail.
If the tree does not have a power supply (it just has a wall plug), then there is typically a small fuse in the plug that may have failed. Finally, if this is an incandescent lamp type, you will be in for a LOT of testing, I spent almost 2 hours last Christmas finding 3 burnt out lamps.