Table of Contents 
C Series Maintenance Manual Rev.2  vii 
C4 Series Maintenance 
1. Safety Maintenance  3 
 
2. General Maintenance  5 
2.1  Maintenance Inspection ............................................................................ 5 
2.1.1    Schedule for Maintenance Inspection ........................................... 5 
2.1.2  Inspection Point ............................................................................. 6 
2.2  Overhaul (Parts Replacement) ................................................................. 8 
2.3  Greasing.................................................................................................. 10 
2.4    Tightening Hexagon Socket Head Bolts ................................................. 12 
2.5    Layout of Maintenance Parts .................................................................. 13 
 
3. Covers  14 
3.1    Arm #1 Top Cover................................................................................... 15 
3.2    Arm #1 Side Cover.................................................................................. 15 
3.3    Arm #2 Side Cover.................................................................................. 16 
3.4    Arm #3 Head Cover ................................................................................ 16 
3.5    Arm #3 Bottom Cover ............................................................................. 17 
3.6    Arm #4 side cover ................................................................................... 17 
3.7    Base Bottom Cover ................................................................................. 18 
3.8  Connector Plate ...................................................................................... 18 
3.9    Connector Sub Plate ............................................................................... 19 
3.10  User Plate ............................................................................................. 19 
 
4. Cable Unit  20 
4.1  Replacing the Cable Unit ........................................................................ 20 
Removal: Cable unit ................................................................................ 22 
Installation: Cable unit............................................................................. 29 
4.2  Connector Pin Assignments ................................................................... 48 
4.2.1  Signal Cable ................................................................................ 48 
4.2.2  Power Cable ................................................................................ 54 
4.2.3  User Cable .................................................................................. 57 
4.2.4    Color of Cables............................................................................ 57 
 
5. Joint #1  58 
5.1  Joint #1 - Replacing the Motor ................................................................ 59 
Removal: Joint #1 Motor ......................................................................... 59 
Installation: Joint #1 Motor ...................................................................... 61