Checking The Intermediate Circuit Voltage; Checking The Maximum Main Inverter Frequency; Filament Current Measurement; Checking The High Voltage Kvsoll And Kvist - Siemens MULTIMOBIL 10 Troubleshooting Manual

3.4

Checking the Intermediate circuit voltage

Measure the voltage on the D970A or D971 PCB across the capacitor using the
digital Multimeter. It should be 355 V dc (+ 10 V / - 5 V dc).
3.5

Checking the maximum main inverter frequency

Turn the Unit OFF.
Place the ST Link on D915 so as to short the two terminals.
Connect oscilloscope on D915.TP.REG and D915.TP.GND.
Turn Unit ON. The unit is now in the Service mode.
In the Service Mode of the unit, select the Prog 7.
On activation of this mode by pressing the DL Service Switch on D936, the
radiographic display indicates
AdJ F
Press the Radiographic Exposure switch and monitor REG on the oscilloscope.
The display indicates
F On
No Radiation.
F max= 15 ± 0.5 kHz.
Adjust the maximum main inverter frequency with potentiometer P4 on D915
Turn the Unit OFF. Remove ST link.
3.6

Filament current measurement

Turn the Unit OFF.
Connect oscilloscope to D915.TP.IH
Turn the Unit ON.
After approx. 3 seconds the Stand-by filament current starts & equal to 1.5V ± 0.2V
Trigger exposure with default values for kV and mAs.
Observe the change in voltage level from 1.5 V ± 0.2V to Preheat value approx.2.0V
Note: Preheat value is parameter (kV & mAs) specific. Just observe the change in
level on preheating step.
3.7

Checking the high voltage kVsoll and kVist

Connect oscilloscope to D915.TP.KVS & D915.TP.KV
Turn the unit ON.
Trigger an exposure with the default values.
Siemens Ltd. Med Division India
Service Instructions
Version 4.0
Service Manual
Page 20 of 48