Tektronix 2440, User Manual

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M aintenance— 2440 S ervice
To accurately check components, it is often necessary
to remove or partially disconnect the component from the
circuit board, in order to isolate it from surrounding cir­
cuitry. Partial specifications (resistor tolerance, transistor
type, etc.) for most components can be found by referenc­
ing the component designation number in the “ Replace­
able Electrical Parts.” Also see Figure 9-1 for component
value identification and Figure 9-2 for semiconductor lead
configurations.
12. R e p a ir a n d A d ju s t th e C irc u it
If any defective parts are located, follow the replace­
ment procedures given under “ Corrective Maintenance” in
this section. After any electrical component has been
replaced, the performance of that circuit and any other
closely related circuit should be checked. If work has been
done on the power supplies, a complete check of the regu­
lated voltages should be done to verify that the supply
voltages are in tolerance. A check of the Display
ADJUSTS calibration and a SELF CAL should verify that
the instrument meets Performance Requirements if the
voltages are all correct.
CORRECTIVE MAINTENANCE
INTRODUCTION
Corrective maintenance consists of component replace­
ment and instrument repair. This part of the manual
describes special techniques and procedures required to
replace components in this instrument. If it is necessary to
ship your instrument to a Tektronix Service Center for
repair or service, refer to the “ Repackaging for Shipment”
information in Section 2 of this manual.
MAINTENANCE PRECAUTIONS
To reduce the possibility of personal injury or instru­
ment damage, observe the following precautions:
1. Disconnect the instrument from the ac-power source
before removing or installing components.
2. Verify that the line-rectifier filter capacitors are
discharged prior to performing any servicing.
3. Use care not to interconnect instrument grounds
which may be at different potentials (cross grounding).
4. When soldering on circuit boards or small insulated
wires, use only a 15-watt, pencil-type soldering iron.
5. Use an isolation transformer to supply power to the
2440 if removing the shield and troubleshooting in the
power supply.
OBTAINING REPLACEMENT PARTS
Most electrical and mechanical parts can be obtained
through your local Tektronix Field Office or representative.
However, many of the standard electronic components can
usually be obtained from a local commercial source.
Before purchasing or ordering a part from a source other
than Tektronix, Inc., please check the "Replaceable Elec­
trical Parts” list for the proper value, rating, tolerance, and
description.
6-11