Bad motors do happen, and you can get a replacement, or have it repaired. The Rainbird 1260Bi is a suitable replacement, and safer to fiddle with, because, unlike the Imperial Valet, the controller runs off the plug-in 24VAC transformer, and has no line voltage on the switches and motors.
This sort of controller costs several times what an entry-level solid-state controller does, so you almost need to be in a lightning-prone area to require one.