Tektronix 684A User Manual

Page of 294
Removal and Installation Procedures
6–46
TDS 684A, TDS 744A, & TDS 784A Service Manual
Procedures for Inner-Chassis Modules
You should have completed the Access Procedure (page 6–15) before doing any
of the procedures for the Inner-Chassis modules. The procedures are presented in
the following order:
A16 Low Voltage Power Supply
A30 Display Assembly and Supply Fuse
Front Subpanel
Main Chassis
1. Assemble equipment and locate modules to be removed: Have handy a
screwdriver with a size T-15 Torx
R
 
tip (Items 1 and 2). Locate the modules
to be removed in the locator diagram Inner-Chassis Modules, Figure 6–2,
page 6–13.
2. Orient the oscilloscope: Set the oscilloscope so its bottom is down on the
work surface and its rear is facing you.
3. Remove the low-voltage power supply: 
CAUTION. If any RTV Silicon is removed from the oscilloscope, it must be
replaced in order to maintain the warranted characteristics for random
vibration.
a. Working from the rear of the oscilloscope, remove the two screws
securing the low-voltage power supply to the rear chassis. See Fig-
ure 6–21.
b. Now, working from the top of the oscilloscope, remove the seven
screws, indicated in Figure 6–21, that mount the supply to the main
chassis.
c.
Grasp the supply at the points indicated in Figure 6–21 and lift the board
up out of the oscilloscope to complete removal.
4. Reinstallation: Do, in reverse order, substeps 3a through 3c reversing each
step to reinstall the low-voltage power supply. Then see the following
procedures to complete the reassembly:
Top Cover and Board Brackets (page 6–37)
A11 Processor/Display Board (page 6–36)
H If option 05 is installed, A29 Video Trigger Board (page 6–32)
A16 Low Voltage Power
Supply