Hitachi IJ PH Service Manual page 4

3. Maintenance of controlling part ·····················································································3-1
3.1 Construction of controlling part ·············································································3-1
3.2 Controller part ·········································································································3-3
3.2.1 EZJ124 board (controller board) ·······································································3-3
3.2.2 Battery ···············································································································3-7
3.2.3 Power supply for LCD backlight········································································3-8
3.2.4 Control panel ·····································································································3-8
3.2.5 Front panel assembly Replacement Procedure ··············································3-9
3.2.6 LCD assembly Replacement Procedure···························································3-13
3.3 Engine part···············································································································3-18
3.3.1 EZJ93 board (MPU board)················································································3-18
3.3.2 EZJ106 board (NH board)·················································································3-22
3.3.3 EZJ95 board (I/O board) ···················································································3-23
3.3.4 EZJ99 board (Optional board) ··········································································3-26
3.3.5 Multiple Power Supply
3.3.6 High voltage power supply ··············································································3-30
3.3.7 Fan Replacement Procedure ··········································································3-31
3.3.8 Exhaust Filter Replacement Procedure ··························································3-33
4. Maintenance of Circulation System ·············································································4-1
4.1 General Structure of Circulation System ·································································4-1
4.2 Main Ink Tank Replacement Procedure···································································4-4
4.3 Pressure Relief Valve Replacement Procedure ······················································4-6
4.4 Joint Structure and Handling ···················································································4-8
4.5 Pump Unit Replacement Procedure ········································································4-10
4.6 Solenoid Valves Replacement Procedure ·······························································4-12
4.7 Pressure Sensor Replacement Procedure······························································4-14
4.8 Circulation Unit Replacement Procedure ································································4-15
4.9 Troubleshooting when Fault Occurs in Viscometer·················································4-18
4.10 Print Head Replacement Procedure······································································4-23
4.11 Troubleshooting Procedure for the Circulation System ·········································4-25
4.12 Repairing Method When the Circulation Route Is Dry or Sticks····························4-30
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