iOptron CEM40 Replacement

May 17, 2019
Due to the internal cable wiring, there will be some disassemble effort to perform this inspection.
Tool needed: Metric Allen wrench set
1. Rotate the mount RA axis to horizontal position as
shown below. Lock the Gear Switch. Use a 2.5mm
Allen wrench to release two DEC motor plastic
cover screws. Remove the DEC cover.
2. Remove the plastic cover. Check the 4-wire plug
marked Main on the side. Make sure it is plugged in
firmly. Power on the mount to see if the DEC
connection error disappears.
3. Remove the RA/Main board cover.
CEM40 Board Replacement
4. Unplug the RA board from the main board.
5. Unplug the cables from the RA board and PEC
6. Remove the RA motor by release three socket
RA Board
encoder cable from the mount. （EC model has a 6-
wire encoder cable）
screws.
PEC cable