Siemens MOBILETT Plus - High Voltage and Single Tank Diagnosis; High Voltage Circuit Testing

6 - 1
Siemens-Elema AB SPR8-215.898.01 Page 1 of 12 MOBILETT Plus / - E/ - M
Solna, Sweden Rev. 05 01.02 SPS-UD
HT and single tank error diagnosis 6
Tests and measurements in the high voltage circuit 6
• Connect the oscilloscope measurement cables to measuring points HTPOS and HTNEG
or HT on D1.
• Adjust the trigger point to the falling edge of the high voltage curve and set the time to
20 - 50 ms/Div.
• If the high voltage cannot be displayed, check the tube current at measurement point
MAPOS on D1. Check the inverter current with an external current transformer.
• Measure HTPOS and HTNEG on D1. Record the fall times (90 - 10% of HT), high
voltage levels and whether the exposure was interrupted prematurely. Compare with
fig. 2 "HT signal, inverter and single tank normal".
• Measure the inverter current using an external current transformer and the HT. Compare
with fig. 1"HTPEAK and inverter current, inverter and single tank normal".
• In case of an error, compare the oscillogram with Fig. 1 "HTPEAK and inverter current,
inverter and single tank normal"