@smsff7: I'm in agreement with you. If I did not know any better, I would say that the person who performed the jack swap inadvertently set the soldering iron in the wrong spot and burned it himself/herself and was too proud (or ashamed) to admit the blunder. Otherwise, they would have seen the burn mark before finishing their diagnosis and ordering the replacement part.
Either way, I'm a laptop repair technician, and if it isn't repairable and they bring it to me, I don't even charge them for disposing of the laptop. I do charge $50 for data retrieval if the customer brings in their own external drive to transfer the files, -OR- I remove the hard drive and hand it to them for free.
The last laptop repair I performed, I allowed the customer to observe and I explained things that she was curious about. This HP laptop, a dv9000 series, also was not receiving power input. After removing the jack and running continuity tests on the jack's printed circuit board, which checked out okay, I then checked the jack contacts with the board's four-wire connecting cable to the motherboard and determined that the female plug's internal spring was not making full contact on two of the four pins on the motherboard. I removed the wires from the connector, spread them a bit, replaced them in the connector and hooked up the power supply. Being successful, we re-assembled the unit and found that the laptop had not been turned on since April of 2010. This was about a month ago I repaired it.
Total time: 70-80 minutes
Total cost: $40