yes the nylon rope and tape all have a tendancy to wear, or even melt if the charger gets to hot. Replace your twine and recheck all your insulators and last check your ground rod, if ground rod is rusty it wont work. The big problem with all tapes and ropes is that they use small tiny wire filaments for the conductor. Check with kencove fencing, here on the net, they have superior products than the farm stores, they also carry a white 12 ga hi tensile electric wire for horses that will last for years.
hope ive been some help
josh

Is that a gradual drop off in punch or is it abrupt? If it is abrupt then it is probably the result of a break in the conductor, if it is gradual look to corrosion and the like.

You can 'test' if a short circuit is occuring along an electric fence by walking the length of it with a portable radio tuned off-channel. The normal static sound will be be replaced by an arcing electrical sound when you hit the point where it's shorting out.

My guess would also be a break in the conducting filaments, but I have found where the force of an animal brushing against the stakes have caused the wires to slip off the proper placement of an insulator and a dead short to ground occurring.

I am not familiar with the tapes, so don't even know if you can fix them by splicing, but you may want to read a bit on the link I provided. It gives good info on troubleshooting voltage problems on fences.

Here is a link that might be useful: Manitoba Forage Council

Don't be so quick to sell your fence (tape or rope)out. One of my best pastures is built with the cheapest band I found at the time (10 years ago)and has been patched and spliced plenty since. What kind of posts are you using? If you want to be sure, get off anout 130 bucks and get you a Gallagher Smartfix. Best ducky's you'll ever spend. I believe you have a ground somewhere. Go out at night and look for sparks.

Good luck.

Dave

Check that the wire to ground rod is making a good connection. Sometimes the ground rod, ground rod clamp's screw, get corroded with mixed metal connection. This corrosion can cause the failure in grounding.

Perhaps you don't have enough ground rods or they are not in deep enough or hooked together correctly. A broken wire or something touching them, causes a problem. Dry ground dirt can cause failure of the ground rods, so watering the dirt around the rods can make them work better.

A bad insulator on a post, cracked or wet, could be bleeding off the power into the post, grounding out the wire past the post.

As a last resort, you might have an electrician out to check things over for you. Trained eyes will spot things you don't even notice.

Just splice the wire where you think the power stops, or take a peice of wire about 2 feet long and twist it over the area where you have the power stopping. Go a foot to each side. I do this quite often. We run our main pasture lines with the higher end GALLAGHER brand fencers. Thed put out a punch no one would hold onto.