921 with no sat lock

[Curmudgeon]

It started with timers not firing.
Now, for the last two days, the 921 does not display video or audio, but a black screen with the "lost satellite lock" message. It seems to occur whenever there's a program recording (red light on".)
My other boxes on the same antennas are working fine and have no problem finding a signal.
I can regain audio and video by doing a "plug-pull" reset.
Obviously, something bad is going on inside the 921. Having never needed to contact dish tech support, can someone provide pointers on the easiest way to get this thing replaced....or is there something else I need to do to correct the problems I've described?!
Thanks

Gary

[Michael P]

Have you done a switch test? That is the very first thing you need to do whenever you get a "no lock" situation (unless there is a "rain fade" situation).