Replacements; Standard Parts; Special Parts; Transistors And Integrated Circuits - Philips SCOPEMETER PM93 Service Manual

7 - 40 CORRECTIVE MAINTENANCE
7.2 REPLACEMENTS
7.2.1 Standard parts
Electrical and mechanical parts replacements can be obtained through your local FLUKE/PHILIPS
organization or representative. However, many generic electronic components can be obtained from
other sources. Before purchasing or ordering replacement parts, check the parts list for value,
tolerance, rating, and description.
NOTE: Physical size and shape of
a
component may affect instrument performance, particularly at
high frequencies. Always use direct-replacement components, unless it is known that
a
substitute will not degrade the instrument's performance.
7.2.2 Special parts
In addition to the standard electronic components, some special components are used:
- Components, custom manufactured or selected by FLUKE/PHILIPS to meet specific performance
requirements.
- Components that are important for the safety of personnel.
NOTE: Both type of components may only be replaced by components obtained through your local
FLUKE/PHILIPS organization or representative.
7.2.3 Transistors and integrated circuits
Some notes on handling these components:
- Do not replace or swap semiconductor devices unnecessarily, because the change may affect the
calibration of the instrument.
- When a device has been replaced, check the circuit that may be affected for proper operation. See
also the Performance Verification Procedure in chapter 4.
7.2.4 Static-sensitive components
In the ScopeMeter the black/yellow "static-sensitive components" symbol is present (see also figure
7.4). This means that this instrument contains electrical components that can be damaged by
electrostatical discharge. Although all MOS integrated circuits incorporate protection against
electrostatic discharge, they nevertheless can be damaged by accidental overvoltages.
Figure 7.9 Static-sensitive symbol (black/yel/ow)