Siemens MULTIMOBIL 2.5 Troubleshooting Guide

MULTIMOBIL 2.5

Troubleshooting Guide

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English Print No.: SPR8-X01.840.01.01.02 Doc. Gen. Date: 09.05

Replaces: n.a.

Multimobil 2.5

Service Manual

Service Instructions

Med

Service Instructions

Version: 6.0

Siemens Ltd. Med India Version 6.0

The reproduction, transmission or use of this document or its contents is not permitted without express written authority. Offenders will be liable for

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Service Manual

Service Instructions

INDEX

7 SERVICE .........................................................................................................................7-3

7.1 TROUBLESHOOTING .......................................................................................................... 7-3

7.1.1 Tools and measuring instruments required...................................................................7-3

7.2 CONTROL VOLTAGES .......................................................................................................7-3

7.3 SIGNALS........................................................................................................................7-3

7.4 HT CHECK ..................................................................................................................... 7-4

7.5 CALIBRATION..................................................................................................................7-4

7.5.1 kVp Measurement.....................................................................................................7-4

7.5.2 mA / mAs Measurement ............................................................................................7-5

7.6 TROUBLESHOOTING .......................................................................................................... 7-5

7.6.1 Checking the line voltage ...........................................................................................7-5

7.6.2 Checking the fuses ...................................................................................................7-6

7.6.3 Checking the LEDs on D920......................................................................................7-6

7.7 CHECKING THE CONTROL VOLTAGES....................................................................................7-7

7.7.1 Checking the Intermediate circuit voltage....................................................................7-7

7.8 CHECKING & SETTING THE MAXIMUM MAIN INVERTER FREQUENCY ................................................7-7

7.9 FILAMENT CURRENT MEASUREMENT ......................................................................................7-8

7.10 CHECKING THE HIGH VOLTAGE KVSOLL AND KVIST ..................................................................7-8

7.11 SETTING THE MAXIMUM FILAMENT FREQUENCY ........................................................................7-8

7.12 CHECKING THE TUBE CURRENT.............................................................................................7-8

7.13 CHECKING THE KV AND TUBE CURRENT (JR)...........................................................................7-9

7.14 CHECKING THE MAS VALUES...............................................................................................7-9

7.15 ADJUSTING THE MAS......................................................................................................... 7-9

7.16 SWITCHING THE COLLIMATOR LIGHT ON................................................................................7-9

7.17 PROGRAM MODES FOR SERVICING. ......................................................................................7-9

7.17.1 Program 1.......................................................................................................... 7-10

7.17.2 Program 2.......................................................................................................... 7-10

7.17.3 Program 3.......................................................................................................... 7-10

7.17.4 Program 4.......................................................................................................... 7-10

7.17.5 Program 5.......................................................................................................... 7-10

7.17.6 Program 6.......................................................................................................... 7-11

7.17.7 Program 7.......................................................................................................... 7-11

7.18 CODES ...................................................................................................................... 7-12

7.19 SPECIFIC CODE HANDLING.............................................................................................. 7-13

7.19.1 Unit not turning ON.............................................................................................. 7-13

7.19.2 No Radiography................................................................................................... 7-15

7.19.3 No Standby........................................................................................................ 7-17

7.19.4 Initialisation CODEs............................................................................................ 7-18

7.19.5 Standby CODEs ................................................................................................. 7-20

7.19.6 EXPOSURE CODES........................................................................................... 7-27

7.20 PCB LAYOUT DRAWINGS ............................................................................................... 7-36

7.20.1 Master Card D915 ............................................................................................... 7-36

7.20.2 Interface PCB D920 ............................................................................................ 7-37

7.20.3 Inverter Card D61................................................................................................ 7-38

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Service Instructions

7 Service

7.1 Troubleshooting

7.1.1 Tools and measuring instruments required

• Usual service tools

• Digital multimeter

• 2 channel storage oscilloscope with 2 probes and 1 current probe

• mAs meter

• Protective ground wire and leakage current tester: Bender safety tester

• Radiation detector

During Oscilloscope operation the protective ground wire connection in the

power cable must not be interrupted under any circumstances.

For measurements where ground loops that may be present could impair the

measuring result, use the Tek amplifier and the trigger attachment .

CAUTION

7.2 Control Voltages Voltage Measuring Point Range

+5 V D915.X15.4 4.8V to 5.2V +15 V D915.X15.5 13.5V to 16.5V

-15 V D915.X15.7 -13.5V to –16.5V +24 V(For Filament) D920 X4.7 &4.8 23 V to 25.5 V Collimator Supply D920.X12A/B 12V ac to 16V ac

7.3 Signals

Signal Measuring Point Range Adjustment

Kvsoll D915.TP.KVS

2.0 ± 0.1 V for 60kV D915.P7

During Exposure

Masoll D915.TP.JRS

2 V ± 0.1 V for 60kV D915.P6

During Standby

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Presence of High Tension.

Service Instructions

Signal Measuring Point Range Adjustment

IH D915.TP. IH

D915.P5

During Standby 2 V ± 0.1 V During Preparation 3.8 V ± 0.3 V (For critically

damped mA)

Fmax D915.TP.REG point

9.2 kHz ± 0.3 kHz D915.P4

during exposure

7.4 HT Check

WARNING

Use Radiation Protection.

7.5 Calibration

It is advisable to re-calibrate the unit in case of undershoot or overshoot observed in the mA waveshape. Recalibration is required when the single tank is replaced.

7.5.1 kVp Measurement

The kVp measurement can be carried out either by kVp-meter or by electrical measurement.

7.5.1.1 kVp-meter

Switch the unit ON. Insert the kV sensor into collimator channel and connect the cable to the meter. Open collimator flaps such that the sensor is well covered by the field. Set the kVp meter at 12pulse and 55-85kV range. Set exposure parameters as 60kV 20mAs. Release an exposure. The radiation LED will light up during exposure. The meter will read 57-63kV. Repeat with meter setting 77-150kV and exposure parameter setting as 90kV 20mAs. The meter will read 85.5-94.5 kV.

7.5.1.2 Electrical

Connect oscilloscope at D915.TP.KV. Set the exposure parameters as 60KV 2.5mAs. Release an exposure. The recorded waveform will read 2.85 - 3.15V. Repeat with 90kV 1.6mAs. The recorded waveform will read 4.27 - 4.75V. Lower kV indicates error in kVsoll / kVsensing / kV-regulator OR high mA.

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Higher kV indicates error in kVsoll / kV sensing / kV regulator.

7.5.2 mA / mAs Measurement

mAs measurement could be carried out either by mAs-meter or by electrical measurement.

7.5.2.1 mAs-meter

Remove mAs link on D920. Insert mAs-meter leads in the banana sockets mA+ and mA- on D920. Set meter in the mAs mode at 200mAs. Set exposure parameters as 60kV 20mAs. Release an exposure. The meter will read 19 - 21mAs. Repeat for exposure parameters 90kV 16mAs. The meter will read 14.4 to 17.6mAs. The actual tube current can be measured by setting the meter in mA mode. Set the exposure parameters as 60kV 50mAs. Release an exposure. During the exposure, the meter will read 23 - 27mA.

7.5.2.2 Electrical

Connect oscilloscope at D915.TP.JR. Set exposure parameters as 60kV 2.5mAs. Release an exposure. The recorded waveform will read 1.58 - 1.62V. The exposure time will be 76 - 84mS.

Lower mA indicates error in mAsoll / mAsensing / mA regulator circuit. Higher mA indicates error in mAsoll / mA sensing / mA regulator OR Low kV. Incorrect mAs indicates Error in timer.

7.6 Troubleshooting

In case of CODEs which Impair radiography, perform the following checks.

7.6.1 Checking the line voltage

Measure the supply voltage at site using the digital multimeter. Ensure that the supply conditions

• Voltage

• Frequency

• Mains Resistance

are within limits as specified in the Technical Specifications for the Unit. Switch the Unit ON

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Service Instructions

If the Unit can not be switched ON Check Supply at Socket.Check Continuity of mains cable with the Plug

NOTICE

pins.Check Over Current Protective devices MCB and U1 & U2.

Switch the Unit OFF.

7.6.2 Checking the fuses

Open the front cover of the control unit . Loosen the Fuse carriers which are mounted on the base of the control unit and check the continuity of fuse link . If fuse link has responded for overcurrent replace the Fuse Link.

Checking the fuses on D920 F1 0.25 AT T1 transformer primary

F2 0.630 AT 240 V for X-ray table. F3 0.630 AT 24 V for K3,K4,K5 relays F4 10 AF Collimator supply F5 4 AT Filament circuit.

7.6.3 Checking the LEDs on D920

Switch the Unit ON. After the initialisation, the default data 60 kV and 10 mAs are displayed at first time switch ON or last stored kV & mAs value.

7.6.3.1 Standby mode

On D920 the following LEDs are illuminated : V3 Main line voltage 240 V.

V9 Presence of 240V. V12 Presence of 24 V for relay V15 Presence of 12 V for collimator V25 Presence of 24V for filament circuit

7.6.3.2 Preparation ON

On half press of exposure release switch unit should go in preperation mode. In addition, V22 (green) lights up on D915.

7.6.3.3 Exposure Mode

On the second step of exposure release switch ,unit enters in radiograpy mode. In addition, V23 (green) for exposure lights up on D915.

7.6.3.4 CODE message

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Service Instructions

V24 (red) lights up on D915 and CODE no. will be displayed on 7 segment display. This will alternate with the kV and mAs values selected.

7.7 Checking the Control Voltages

When the unit is ON relay K2 on D920 are ON. SMPS placed in the Inverter module gets supply, Measure the DC voltages at X15 connector of D915 PCB.

Pin No. Signal Name Input/Output max. permissible

voltage/current 1 D gnd Input 0V 2 -nc- -nc- 3 D gnd Input 0V 4 DC supply Input + 5V 5 DC supply Input +15V 6 A gnd Input 0V 7 DC supply Input -15V

-nc- = No Connection

7.7.1 Checking the Intermediate circuit voltage

Depending on the supply voltage, a value between 250 to 350Vdc must be measured with the digital multimeter across the parallel capacitors C1,C2,C6,C7 and C9(if present) in inverter module.

7.8 Checking & setting the maximum main inverter frequency

Turn the Unit OFF. Place the ST link on D915 so as to short the two terminals.

Make the unit ON. The unit enters SERVICE mode. In the service mode of the unit ,select Prog 7 by using the KV switches. On activation of this mode by pressing the DL-serv Key , the display indicates

Adj F

Press the Radiographic exposure switch and monitor REG on Digital storage Oscilloscope at Reg Test Points.

The display indicates

F On And max. Inverter firng frequency will be displayed on Oscilloscope. Adjust REG for 9.2 kHz ±0.3kHz by using P4 on D915 card After adjusting the frequency switch off the unit and remove ST link on D915 card .

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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

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.

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Service Instructions

7.13 Checking the kV and tube current (JR)

Connect oscilloscope to D915.TP.KV & D915.TP.JR Turn the unit ON. Trigger an exposure with the default values. Observe the voltage on CRO (1V = 20mA & 1V=20kV) for selected kV & mAs .

7.14 Checking the mAs values

Turn the Unit OFF. Remove the Shorting Link “mAs +/-” on D920 PCB banana sockets. Connect mAs meter to “mAs +/ mAs-” on D920 PCB. Turn the Unit ON. Trigger the following exposures:

Setting at control panel Valid mAs values

40kV,200 mAs 190..210 mAs

66kV,100mAs 95...105 mAs

90kV,1mAs 0.9.....1.1mAs

Turn the Unit OFF. Remove the mAs meter and reinsert the Link on the D920 PCB.

7.15 Adjusting the mAs

Turn the Unit OFF. Remove the Shorting Link “mAs +/-” on D920 PCB banana sockets. Connect mAs meter to “mAs +/ mAs-” on D920 PCB. Turn the unit ON. Trigger the exposures for default kv & mAs settings. Observe the mAs meter reading and if it is not within the tolerance (specified in the Technical Specifications) of set value adjust the P1 on D915 card

7.16 Switching the Collimator Light ON

Switch ON Collimator Lamp. The Halogen lamp will light up and field of light will appear on the target. The lamp will be switched OFF automatically after 30 seconds.

If the collimator lamp is switched ON and OFF several times within a short period, overload protection will automatically switch the light OFF. Cool-down periods are recommended.

7.17 Program Modes for servicing.

To put the Unit into service Mode short the ST link on the D915 and turn ON the unit .The display will show as follows

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Service Instructions

Use the KV + or KV – switch to move to any program (PR 1 to PR7) Use the DL_Serv switch on the D936 to to select the displayed program.

7.17.1 Program 1

Not Used

1. Short the ST link on the D915 and put the unit on . the display will read as below and enter program mode .

Pr 1

2. This program is not used

7.17.2 Program 2

To check the total number of exposures taken .

Service Manual

1.The display on the D932 will be as below.

XXX XXX

XXX XXX corresponds to the total number of exposures taken on the unit.

7.17.3 Program 3

To check the type of codes that occurred in the unit (maximum 20) .

1.Press the switch DL-serv on the D936 once.The display will be

AA XX

AA diplays the serial number of the exposures that have occured, in chronological order (max. 20) & XX displays the corresponding codes occured on the unit

7.17.4 Program 4

To erase the codes that occurred in the unit

1.Press the switch DL-serv on the D936 once.The display will be

ErA Err

Keep the mAS – key depressed for 4 seconds till the dislay beomes

0 Err

7.17.5 Program 5

To store the Last Value of KV & mAS Display

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LAS VAL

By entering into this program the last value displayed before turning OFF the Unit will be displayed on turn it On the next time .

7.17.6 Program 6

To Display the maimum KV & mAS possible with the Unit

100 200 100 indicates the maximum KV available & 200 indicates the maximum mAS available on the Unit *I n case the display values do not vary in standby by using the key PCB then Enter this program and vary the KV & mAs displayed using the Key PCB D936 Then switch the the Unit OFF and enter standby mode, the unit should function

normally .

7.17.7 Program 7

Adjusting REG frequency. Please refer chapter 7.8 (Checking & setting the maximum main inverter frequency)

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Siemens MULTIMOBIL 2.5 Troubleshooting Guide

Specifications and Main Features

Frequently Asked Questions

User Manual