Siemens MOBILETT Plus HP Service Instructions Manual page 49

HT and single tank error diagnosis
Overview
Faulty curve
Inverter current normal
HT+ discharges
Inverter current normal
High speed HT - discharges
Fig. 7 and Fig. 8
Inverter current normal
High speed HT+ and HT-
discharges
Fig. 6
Abnormal inverter current;
e.g. triangle shaped HT-dis-
charges
Fig. 9 and Fig. 10
Abnormal inverter current
e.g. asymmetric
Fig. 10
Very low tube current
(normal inverter current) (Err
5)
Full output voltage not
obtained after adaptation
Rapid series of voltage
peaks (increasing voltage)
Siemens AG
Medical Solutions
Possible causes
Defective tube
Defective high voltage capacitor (+)
Arching to ground on plus side
Defective tube
Defective high voltage capacitor (-)
Defective filament transformer
Defective insulation on the wires to
the cathode
Arcing to ground on minus side
Defective tube
Defective high voltage capacitor (-)
Arcing between plus and minus
side
Defective high voltage transformer
Defective diode strip
Defective tube
Defective inverter
Connection K64/1 and K64/2
reversed between D13 and single
tank
Defective high voltage transformer Replace single tank
Arcing in HT measurement resistor
or series resistor
SPR8-220.061.03
Rev. 03 09.03
What to do
Replace single tank
Replace single tank
Replace single tank
Replace single tank
Replace inverter
Properly connect K64/
1 and K64/2
Replace single tank
Page 3 of 12 MOBILETT Plus HP
CS PS 24
6 - 3