I now have an RMA and shipping details from Meade for the 14 inch; I should be able to get it out of here next week for repair. The best guess is that it is a controller board issue for the RA drive. The good news is that it may only be away for three weeks, as opposed to six.
I have done a little more work on the 10 inch LXD-55. It seems to be behaving itself now and I may try some imaging tonight if it continues to work well. The LXD-55 mount is a German Equatorial mount ('GEM"). I'm not fond of GEMs, especially with a Schmidt-Newtonian (SNT) design, as the eyepiece of the scope can end up in some very inconvenient positions. Rotating the tube can help, but it is very inconvenient. I am also concerned about the drive itself. I disassembled it, refinished the gears and re-lubed it. The result was smoother slewing, better pointing and tracking, and less vibration. Whether the mount can support deep sky imaging remains to be seen.