iOptron CEM40 Use and care manual

CEM40 Board 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.
4. Unplug the RA board from the main board.
5. Unplug the cables from the RA board and PEC
encoder cable from the mount. （EC model has a 6-
wire encoder cable）
6. Remove the RA motor by release three socket
screws.
RA Board
PEC cable

7. Carefully pull and lift the main board up from the
compartment. Disconnect the DEC and power
cables
8. Replace the board. Wrap the belt over the motor
pulley first. Align the motor mounting holes to the
mounting block. Tighten 3 locking screws.
9. Check the belt tension by gently pushing the belt
down with a finger. It should have about 3mm
movement. To adjust the belt tension, loose 3
screws a little, insert a small screw driver between
the motor and mounting block while tightening 3
screws.
10. Connect the cables and insert RA board back to the
main board. Pay attention to two sets of pins on the
bottom. Make sure they are seated well.
11. Put the cover on. The top of RA board should be sit
in the inside cover slot.
12. Tighten all the screws.
13. The procedure of replacing DEC board is similar to
replacing main board.