Siemens MOBILETT Plus Service Instructions Manual page 47

HT and single tank error diagnosis
Overview
Inverter current normal
HT+ discharges
Inverter current normal
High speed HT - discharges
Figures 7 and 8
Inverter current normal
High speed HT+ and HT-
discharges
Figure 6
Abnormal inverter current;
e.g. triangle shaped HT-dis-
charges
Figures 9 and 10
Abnormal inverter current
e.g. asymmetric
Figure 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-Elema AB
Solna, Sweden
Faulty curve 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
SPR8-215.898.02
Rev. 01 01.02
What to do
Replace single tank
Replace single tank
Replace single tank
Replace single tank
Replace inverter
Connect K64/1 and
K64/2 properly
Replace single tank
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SPS-UD
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