Another Lionel Lionchief Sound Issue Corrected

Caution, a huge risk is if the black speaker wires ever break and touch that blue wire- poof goes your board quicker than you can blink.

That's why I feel this is a bigger problem- yes annoying to have the sounds cut out, but a totally different situation when the failure blows the board sky high.

When I have encountered similar situations as yours...once I re solder I apply epoxy to the area and a short distance up the wire.

Seems like it might be the right situation to use some black liquid electrical tape over the wires to prevent that situation from happening.

I personally use marine grade heatshrink with hot glue on the inside. The logic behind this is, the glue helps strain relief the wires, but more importantly, is possible to remove later- just in case the wire does fail or a repair is needed. A drop of alcohol does not dissolve the hot glue, but does break the bond between it and anything else. My concern with more permanent solutions, they pretty much are a one and done- the next repair now you have to replace the entire thing.

And, again, my concern is, the design and strain relief- the likelyhood of a related but different failure of the wire is semi-likely in the long term life of the loco- especially if it keeps going around the small loop or oval of track. That straight, then curve, then straight, then curve just beats these to death over the lifetime of the loco.

It's not high strand count flex rated wire, it's not a properly designed joint for flexing, and even when we do these repairs and make the mods, the stress is still there- just moved a few mm down the wire at most.

My experience with dried liquid electrical tape is that it's fairly easy to scrape off should another wire fail and I have to go back and make a similar repair again, but the hot glue and shrink wrap also works.

You're right, of course, about the repair itself. We're merely treating the symptoms that show up as a result of poor design and the underlying root cause remains.