Corrective Maintenance; Diagnostic Testing And Troubleshooting; Introduction; Troubleshooting Techniques - Philips SCOPEMETER PM93 Service Manual

CORRECTIVE MAINTENANCE
7 - 1
7 CORRECTIVE MAINTENANCE
7.1 DIAGNOSTIC TESTING AND TROUBLESHOOTING
7.1.1 Introduction
The Scope Meter provides semimodular design to aid in troubleshooting. This section describes
procedures needed to isolate a problem in a specific functional area. Finally, troubleshooting hints for
each functional area are presented.
If the ScopeMeter fails, first verify that you are operating the ScopeMeter correctly by reviewing the
Operation Verification Procedure found in the Users Manual.
WARNING: Opening the case may expose hazardous voltages. Always disconnect the
instrument from all voltage sources and remove the batteries before opening the
case. Remember that repairs or servicing should 'be performed by qualified
personnel only.
7.1.2 Troubleshooting techniques
If a fault appears, the following test sequence can be used to help you to locate the defective
component:
- Check to verify that the control settings of the instrument are correct. Consult the operating
instructions in the Users Manual.
- Check the equipment to which the instrument is connected and check the interconnection cables.
- Verify that the instrument is properly calibrated. If it is not, refer to Chapter 5: "Calibration
Adjustment Procedure".
- Locate the circuit(s) in which you suspect the fault: the symptom often suggests the faulty circuit.
If the power supply is defective, the symptom may appear to be caused by several circuits.
- Check the circuit(s) in which you suspect the fault. Often it is possible to find faults such as cold
or defective solder joints, intermittent or open interconnection plugs and wires or damaged
components.
- Firmware releases V3.15 or lower are not compatible with units having analog boards A2 with
modification sticker 22 or higher. The software must be updated to a higher version.
See Section 11 " MODIFICATIONS", Digital A1 PCB STICKER 22.