This is an ultrabook by the looks of things, with a 65W charger. If it did burn out at only 4V over, the cost of repair on a base model is close to the cost of a replacement. And if it went out at only 4 over, do you really want it?
If it's under warranty you could try to get it repaired, but Lenovo contracts out repairs to third party companies that rarely hire skilled workers for cost reasons, and are more concerned about churning out units than making sure they actually work.