HP 182C - Page 68

Model
182C
Service
2
SCREWS
RELEASE 3
FASTENERS ON EACH
TILT
SIDE
Figure 8-2.
Cover
Removal
&51. POWER
MODULE REMOVAL.
8-52.
The
low voltage
power
module includes the power
transformer, low voltage rectifier assembly, low voltage
regulator assembly, and the series regulators. The entire
module is removable as a unit which can be further
disassembled If desired.
8-53.
To remove the
power
module, disconnect ac power
input,
remove
the
covers and proceed
as follows:
e. Remove
module by grasping filter
capacitors on
each
side and pressing toward rear
of instrument.
If CRT
filament leads were not
disconnected previously,
be care-
ful 10 pull module
only partially Tree, ihen disconnect
filament leads and remove
module.
8-54.
CONTROL
ASSEMBLY
REMOVAL.
8-55.
This assembly irwiudes
the calibrator,
CRT
controls,
and LINE power switch.
8-56. To remove the Controls assembly, disconnect ac
power
input, remove the covers, and proceed
as
follows;
a. Disconnect 5 square-pin connections
between cable,
located on the ur>dersidc of
the assembly, and the Inter-
connect assembly
circuit board.
b.
Disconnect
8
square-pin connections
located on the
top side of the assembly. Use
a
long-nosed pliers and pull
connections straight off to remove. These consist
of; CRT
focus
(2
right-angle connections), trace alignment
(2
connections). CRT flood gun
{2
connections), CRT mesh,
(1 connection), and ground (1 connection).
c.
Remove 4
screws
from
underside of Control assem-
bly. Two screws hold
the assembly to the front casting
frame and also hold
the focus high voltage shield in place.
The other
2
screws are
located approxinnately at the center
of the assembly.
d. Grasp the assembly Internal
to
the
instrument and
remove with a straight
Dull toward the front of the
instrument.
Do not remove by pulling on knobs. Be care-
ful that
square-pins located on
top
of the
assembly do not
catch
on
front
casting frame.
8-57.
AC POWER INPUT MODULE
REMOVAL.
a. Set the instrument on rear end.
b. Remove 4 screws located on bottom rear
of instru-
ment.
8-58.
The
power input
module
contains the
line power
jack, line filter,
fuse holders
and LINE
SELECTOR
switch,
It may
be partially
removed for
servicing or
completely
removed if
necessary.
c.
Return instrument to horizontal position and remove
2 rear screws. One screw is
located
on top
of each series
regulator heat sink. Do not remove screws holding rear
feet
to
heat sink or screws located below rear feet.
d.
Disconnect CRT filament lead connectors (brown
wiles)
fium lectifiei assembly using long-nosed pliers and
lifting straight up. (CRT
filament leads
may
also
be
disconnected later,
refer
to step e.)
Filament leads
operate
at 3150
Volts
when power is on.
8-59. Partial removal is
possible since the
cable carrying
ac line power
is
long
enough
to expose the components
without disconnecting
the cable.
To release the module,
disconnect
ac power input and
remove the
2
screws
holding the panel
In place. Pull the module to the rear
of
the instrument.
8-60. If
complete removal is desired, cither remove
the
low
voltage power module
or open the upper
rear panel.
This evposes the
ac line power
cable connections
to the
Interconnect assembly.
Then disconnect
6 square-pin
connections from the
cable to the Interconnect assembly
circuit board.
The module can
now be completely removed
from
the oscilloscope.
8-5