I would like to try and help figure out what is going on with your paper tray issue, but I need to understand exactly what it is that you are trying to do first. Can you explain the issue in more detail? What type of paper is loaded in your trays? When you "open door b to reset it" what does that mean exactly? Those are some of the questions that I need answered so that I can understand what is going on with your machine. You can send me an email with the details at your convenience and I will take a look and see if I can figure something out.
We have a Phaser 7400 that is having trouble on which tray to use for paper. Seems to be some kind of profile issue on certain medias but it keeps happening and then we have to go and open door b to reset it and press the use current media button on the display. Mainly happens when the Apple computers print to it. Thinking it is a saved profile issue on their side, but can't track it down. Any ideas would be greatly appreciated.