i brought my vaio to the shop with the same dc jack problem now its not working at all and the guy in the shop is saying there must be something wrong with the motherboard it wont even turn on now and it was before i brought it to the shop
say goodbye to your warranty if the shop did motherboard repair work. go back to the shop and tell them its not working. if they refuse/can't fix it, get a lawyer, call the better business bureau etc...
depends if you know your lawyer well or not. sometimes just threatening them with a lawyer will get them to do something for you. the reason i brought it up is because the shop has already told them something else was wrong before they brought the laptop in.