Filament Current Measurement; Checking The High Voltage Kvsoll And Kvist; Setting The Maximum Filament Frequency; Checking The Tube Current - Siemens MULTIMOBIL 2.5 Troubleshooting Manual

Service Manual
Service Instructions
Fmax= 9.2 ± 0.3 kHz.
Adjust the maximum main inverter frequency with potentiometer P4 on D915
Turn the Unit OFF.
Connect 9 pin D-type connetor on D920 PCB.
7.9

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 2V ± 0.2V
Trigger exposure with default values for kV and mAs.
Observe the change in voltage level from 2 V ± 0.2V to Preheat value approx
3.8V ± 0.3 V.
Note : Preheat value is parameter (kV & mAs) specific. Just observe the change in
level on preheating step.

7.10 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.
Observe the voltage on C.R.O with the scale corresponding to 1V= 20kV for KV
and 1V =30KV for 30 KVS.

7.11 Setting the Maximum filament frequency

Turn the Unit OFF.
Remove X11 D915.
Connect oscilloscope to D915.TP.CAL
Turn the unit ON
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Wait for the contactor to pick up.Press the DL_serv key on the D936 twice.
Using P3, set the maximum filament frequency on D915 (1.8 KHz to 2.2 KHz))
Note : Duty Cycle of the waveform is varying as the ON time is fixed.
Turn of the Unit.Replace X11 connector on D915 PCB.

7.12 Checking the tube current

Connect oscilloscope to D915.TP.JRS & D915.TP.JR
Turn the unit ON.
Trigger an exposure with the default values.
Observe the voltage on CRO (1V = 20mA) & confirm value for selected kV & mAs.
Siemens Ltd. Med India Version 6.0 7-8
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