This is a repost from a time before AI pics started to flood the internet. Not long before, but I think it’s real.

Look for 3M VHB (very high bond) tape. It’s used to adhere trim pieces to car doors and fenders. Make sure the surface is super clean and warm to the touch before you apply the tape, a cold surface can inhibit the adhesive properties.

If you have access to a spare 120mm computer fan you can print two of these and use it to provide forced air ventilation on the 4" flexible hose.

Nicely done. You know the quality of materials and workmanship that went into your extension. While you can purchase a cheap extension strip from an online retailer for a lot less you can't trust the build quality on most.

I had an issue with a supposed 'quality' surge suppressor years back where one of the outlets was intermittent. First thing I did was replace it, afterwards I tore it apart and checked it out. Instead of solid connections between the copper wires and the metal blades in the outlets they were just pressed together, slots in the metal blades clipped onto bare copper wires. I ended up soldering all of the connections in the strip but I was appalled of the build quality of a $70 name brand surge suppressor.

What system does this work in? Kinda looks like a RAMtek board from a Data General Eclipse S/280 expansion chassis I worked on back in the mid 80s. The black area reminds me of the 2K core memory.

Try swapping lights from the blown section into the working section of the tree. If the previously working section starts working again then you know the bulb was OK. Continue swapping out each bulb in the blown section until you have found the one that doesn't work or the entire string has been tested. If you make it all the way through the blown section and every light tested in the working section are OK then it is a wiring issue that you will not be able to fix easily.

Is the tree assembled as one piece or in multiple parts? I have a two part pre-lit tree, the top section occasionally goes out if it gets rotated a little too far. The top and bottom have a connector in the pole, lifting the top section a little bit and reseating it fixes the problem.

While you may have already decorated the tree you may not be able to get it replaced if you wait until after the season is over. Then you will have a faulty tree to deal with next year if you can't find a fix. It's annoying but you probably have a limited window you can return the tree for a replacement.

If you are able to exchange it, consider a tree with LED bulbs. Incandescent lights are dinosaurs; they generate a lot of heat, use a ton of power and, as you have experienced, if one goes out it can take out the entire string. While you may not get away from the one light taking down the entire string issue (still a thing) they are far less likely to fail than the old glass incandescent bulbs.