Burnt charger cable caused by working while charging?

jdimm wrote:

Two chargers stopped working after a few months of use.

In both cases, the spring-loaded pins 2 and 4 are burnt out and no longer move. The corresponding sockets on the macbook plus are also charred. I got it to work one last time and the plug heated up to burn-your-fingers hot.

The problem goes away if I charge the computer only with the lid closed, then disconnect it during use. Not a major inconvenience. The 2015 battery still gives me a few hours of use. The plug remains cool while charging. I cleaned the sockets with alcohol and a toothpick.

Until now I have always left the charger cable connected all the time. Was that a bad idea from the start, or has something failed in my macbook that makes it bad user behavior now?

Will be checking in at the genius bar today.

If the DC-in board is worn out, it can short out the magsafe new or old.

Report back your findings after your visit to the Apple Store.

Not an expensive repair to replace the DC-in board.