This led me to suspect an intermittent connection was the culprit, and it was quite a poor one at that the high resistance leading to the heat issue. The other, was that even when it would charge, the connector would become very hot. The first was that the charger would only function if the cable was held just so, in exactly the right orientation. However, it’s not the easiest to fix. When the charger began failing, I noticed two symptoms. This connector has many benefits, such as quick release in the event someone trips over the cable, and the fact that it can be plugged in without regard to orientation. Unlike most PC manufacturers, who rely on the humble barrel jack and its readily available variants, Apple liked to use the Magsafe connector on its Macbook line. Such was the case when I found myself face to face with a failed Macbook charger, and figured it’d be a simple fix. It’s usually the connector that goes first.

Combine this with fairly lightweight design and it’s not uncommon for a laptop charger to fail after a few years. They’re repeatedly plugged and unplugged, coiled up, stuffed into bags, thrown around, and just generally treated fairly poorly. However, it seems they also have a version for the USB-C to Magsafe 2 cable which may suit your situation.Laptop chargers face a hard life. Consequently, the cable I bought will not work for you. It appears from the picture you have the newer Magsafe 2 connector. I've been using it for several months now & it works. This cable allows me to use one of the new USB-C chargers to charge my 2011 Macbook Pro. I was able to find this replacement Magsafe cable on Amazon. I also used electrical tape as a temporary solution. The outer insulation in one area on the cable just began breaking down, and falling off the cable! I've never seen wiring insulation behave like this. I had the same problem as you recently on my Magsafe cable. As long as the electrical tape is in place, and in good condition, I don't believe the cable poses any risk to you, or to your Mac. You have done the right thing by mending the cable with electrical tape: it's an insulator and it's flexible. It's important all of the inner wires (inside the shield) are in good condition. However, the insulation on the wires in the cable should be checked for evidence of cracking, fraying or other deterioration. That said, any damage to the shield is unlikely to affect the function of your cable. Using a shield as a conductor would be unusual to say the least. I'm not privy to Apple's designs or schematics, but most likely the shield is there for EMC (electromagnetic compatibility), and not as a current-conducting ground wire. The shield is made from a fine wire that is 'braided', and runs the length of the cable. I guess tha the 'coaxial' part you refer to is actually just a shield.

Macbook pro cable charger frayed