
Maintenance—Type 324
black-and-green plastic indicator plate should be removed
and set aside until re-assembly.
Power Regulator Enclosure
To gain access to the enclosure, remove two nuts and
screws from the front and one screw from the back of the
enclosure cover.
W A R N I N G
■
Dangerous potentials are present in the enclosure
when the oscilloscope is energized.
Fuse. The fuse (operating power) is located at the rear
of the compartment on the component side of the Low
Voltage board. The circuit board must be removed to re
place the fuse. Only 1.6 A 250 V fast blow fuses should be
used as replacements. A spare fuse is provided with the
oscilloscope and is contained in the spare-fuse holder
located near the Attenuator Circuit Board.
Low Voltage Circuit Board.
To remove the Low Voltage
board, remove the three screws from the upper surface and
lift the board up and out, pivoting it on the wiring harness
at the side of the board.
High Voltage Circuit Board.
For access to the bottom of
this board, do the following:
Remove the Low Voltage board. Then unscrew the three
nylon mounting posts and lift the board up and off the
three mounting screws.
Transformer and Toroids.
Leads should be tagged, or a
written record should be made of the connections whenever
these components are removed. The windings can be recog
nized by the point at which they leave the assembly; the
ends can be distinguished either by lead length or by color
code. Do not untwist any of the paired leads.
V O L T S /D IV , T IM E /D IV , FOCUS and IN T E N S ITY
Control Assemblies
The front castings must be loosened and swung down
and forward in order to remove these controls. Proceed as
follows:
Remove the CRT and shield, following the previously
given directions. Using a 1/16 inch alien wrench, loosen two
set screws in the V O L T S /D IV knob and two in the T IM E /
D IV knob. Loosen one set screw in each of the variable
knobs and in the POSITION knobs and the TR IG G E R
knob. Pull all of the knobs (except for the POWER switch)
off their shafts. Remove the front panel from the instru
ment.
Remove the four machine screws which fasten the front
casting of the instrument to the chassis frame posts.
Remove the screw which holds the frame post and
Power Pack toggle clamp to the chassis, and remove the
frame post.
Open the Power Regulator Enclosure and remove the
Low Voltage circuit board. Remove the machine screw
from the top frame post, moving the foil shield as neces
sary. Remove the frame post from the assembly.
The front casting can now be swung down and forward
sufficiently to permit access to, or removal of the controls
under consideration.
LOW BATT Indicator
The indicator lamp is soldered to the base cap which is
snapped in place over the indicator holder. To remove it,
force the cap off the holder.
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