LORAD AFFINITY Series, Руководство по обслуживанию

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P/N 9-500-0255 4-59
Service Manual
Chapter 4: Calibrations and Performance Checks
Maintenance Procedures
9.0 Maintenance Procedures
9.1 kV Control Offset Calibration
This procedure adjusts the kV Control Signal offset to -6.00 V, and should be performed
whenever the Host Microprocessor Board or the HV Generator Assembly is replaced.
1. Turn the unit OFF.
2. Remove the Gantry’s left and right side panels (to access the HV Generator Assembly
and the Host Microprocessor board) as per Chapter 6, Section 2.1.1.
3. On the Host Microprocessor board, set the unit for the service mode (S2 switch 1 = ON).
4. Disconnect the HV cable from the HV Generator Assembly.
5. Verify jumper J7 on the HV Control Filament PCB is installed (refer to Appendix B, Sec-
tion 6.0, Table B-24: HV Control Filament Board (PN 1-003-0485) Jumper Settings).
6. Turn the unit ON.
7. Access Calibration Screen #3 (Figure 4-19), highlight the kV field.
8. On the Control Panel, press the
Reset and Comp Release buttons simultaneously. The
screen will update to show the Adjust kV Offset prompt in the message area, as shown in
Figure 4-19.
Figure 4-19: kV Offset Calibration—Calibration Screen #3
9. Connect a DMM to HV Control Filament board as follows:
• Negative lead to TP41 (GND)
• Positive lead to TP48 (-VP Local)
10. On the HV Control Filament board, adjust R71 for an output of -6.00 V at TP48.
11. Disconnect the DMM.
12. Return the unit to the user mode (S2 switch 1 = OFF).
13. Remove power to unit.
14. Reconnect the HV Cable to the HV Generator Assembly. Replace all covers.