Service; Safety Precautions; Troubleshooting; Tools And Measuring Instruments Required - Siemens MULTIMOBIL 10 Troubleshooting Manual

1 Service

1.1

Safety Precautions :

Before working on the unit ensure that the Mains is switched OFF.
For completely safe working remove mains plug.
The unit must be OFF before removing or putting back the assemblies.
The protective earthing of subassemblies must not be removed in any case.
1.2

Troubleshooting :

1.2.1 Tools and measuring instruments required

• Usual service tools
• Digital Multimeter:
• 2 channel storage oscilloscope with 2 probes and one 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.
1.3 Measuring with oscilloscope :
For normal working, the protective earthing of mains must not be removed.
In case system noise is getting coupled to the scope, use the scope in differential
mode.
To measure high voltage, use DIFFERENTIAL probe isolated from ground.
1.4 Handling precautions
Strictly observe ESD precautions while handling PCBs and ESD sensitive
devices.
After the unit is switched ON, the capacitors C1~C12 on D970A and D971
charge to 355V DC. After switching the unit OFF, it takes about 08 minutes for
capacitors to discharge. The presence of DC voltage is indicated by Green
LED V24 on D950A and also V1 ~ V12 LED's on D970A / D971.
Siemens Ltd. Med Division India
Service Instructions
Version 4.0
Service Manual
Page 4 of 48