Several months ago the lights in my daughter's room starting dimming irregularly as if there was a power drain. In fact, her computer would reboot itself. One day, all power went out. I went to our breaker box and the 20 amp breaker to her room had not tripped. This breaker was a two pole breaker and the 2nd one was open. I fed the hot wire into the open breaker and power was restored. This led me to believe the breaker was bad. Several weeks later it started to happen again and once again the power shut off without the breaker being tripped. I replaced the 2 pole breaker with a new one and everything seems okay again but I am now wondering if there is a bigger problem. I have looked in the attic at the junction boxes and see no obvious signs of a problem. The wiring in the room is done with 12-2 three wire. She has lots of appliances obviously but I don't think it could be too much for a 20 amp breaker. Even if it was, the breaker should have tripped, not gone bad. Any thoughts ?