If you experience motor stalls and power resets here is a troubleshooting list:
1) Cold can impact battery power and also cause decreased power output from 120v/12v power supplies. Test by replacing with fresh batteries or alternate power supply. Check if same problem occurs while the scope is warm.
2) Weight balance. The motors will stall and power will reset if the motors have to strain against improper weight. The scope MUST be balanced in both the horizontal plane AND the vertical plane. The RCX requires a 3D weight counterbalance system. For Horizontal balance slide the weights fore & aft with the tube horizontal. For Vertical balance the weights need to be screwed away from the tube with the tube in the Vertical position.
3) Proper power supply. The RCX400 model requires a power supply of a MINIMUM of 5amps. This was spelled out by Meade in a service bulletin. Less than 5amps can cause all sorts of erratic behavior and may damage the electronics. Erratic behavior can be, but is not limited to, slewing to the stops, power resets, motor stall, focus motor lock-up, dec/atz motor runaway etc.
4) One should probably not bother with attempting to use the internal 'C' batteries to power the scope except for testing purposes and very limited use. The internal batteries run down very quickly.
Pesse (I have a runaway slew...how do I get my RCX pic on a milk carton?) Mist