I’m training my CGE PRO with PECTool and the mount can’t find my worm index.

The worm index is needed by the PECTool or other PEC programs like PEMPro to synchronize the corrections with the turning of the worm gear. The mount can move a couple of degrees during the process. Normally it takes about 10 seconds or less for the PEC worm index sensor to be found by the mount and perhaps 15 more seconds for the mount to return to its original position. If the mount doesn’t find it during this time frame, it probably won’t find it at all.

If the worm index is not found, here are possible reasons.

The sensor itself is malfunctioning.

A bad RA cable connector. Swap Dec and RA cables and try to find the worm index again.

A likely cause is a burned out pin on the motor control board. This is usually the result of hot swapping cables – not powering down the mount when disconnecting RA and Dec cables. Often nothing will happen when a hot swap is done, but it can burn out any of the pins on the board connected to the cable.

If the board is replaced as a part of a mount repair at Celestron, you will get a newer (July 2010) board that has a protective daughterboard that prevents accidental damage to the pins.

Updated 12/27/13