Shimadzu GCMS-QP2010 - Page 82

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V
CP3
should be 1 x conversion dynode setting (kV). Any abnormality in this voltage is
probably due to incorrect D/A voltage from the CPU PCB.
Check that when CD HV is ON, V
CP3
=V
CP1
; when CD HV is OFF, V
CP1
≒ 0V.
If the V
CP1
voltage is generated whether CD HV is ON or OFF, this suggests a defective
controller operational amplifier. Replace the MAIN CTRL PCB.
If V
CP1
= 0V when CD HV is ON, the problem is probably in the high-voltage power supply
assy, or in the connector cables.