I got my broken laptop back today. It took 12 days round-trip to have the repair do nothing. While I was waiting, I ordered an off-brand power adapter from eBay for $13, shipping included. I plugged it in and it works. The power jack is very use, but for now it is working with the new adapter. By the way, a replacement adapter from Toshiba is $99.
When the jack eventually completely fails on my Satellite L305, I will replace it with one from Radio Shack. I made the same fix to my wife’s Satellite A135 last weekend and it is working just fine now.