Tektronix 371B, Service Manual

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Maintenance
4-20
371B Service Manual
The following describes how to remove assemblies from the main unit.
Chapter 8: Diagrams and Component Locations shows the location of related
electrical assemblies and chassis-mounted components. Refer to related drawings
in Chapter 9: Mechanical Parts for location of related chassis-mounted subas-
semblies and components.
CRT Removal.
. Before removing the CRT, check associated circuits to be certain that
removal is necessary.
Use extreme care when handling a CRT. Breakage of the CRT causes
a high-velocity scattering of glass fragments (implosion). Wear protective
clothing and safety glasses. Avoid striking the CRT on any object, that might
cause it to crack or implode. When storing a CRT, place it in a protective carton
or face down in a protected location on a smooth surface with a soft mat under
the faceplate.
The CRT may retain a dangerous electrical charge. Before removing the CRT,
the anode must be fully discharged by shorting the CRT anode to the chassis.
Wait at least 10 minutes and again firmly short the anode to the chassis, then
proceed with the CRT removal procedures.
Perform the following to remove the CRT from the main unit chassis.
1. Remove the rear, top, and left side panels.
2. Loosen the two CRT base clamp screws (at the rear of the CRT) until the
tension of the springs is released (springs are loose on the screws).
3. Remove the CRT base-pin socket from the rear of the CRT.
4. Disconnect the CRT anode cap from the jack located on the left side of the
CRT. Ground the CRT anode to the chassis to discharge any stored charge
remaining in the CRT.
5. Remove the CRT bezel cover from the under side of the CRT bezel by
pulling it off with your fingernail.
6. Remove the two screws exposed on the lower side of the CRT bezel, and
remove the CRT bezel from the front panel.
7. Remove the CRT filter, spacer, and implosion shield from the CRT frame.
8. Remove the four screws located on the inner side of the frame.
Main Unit Assemblies and
Components