Tektronix 2205 Service Manual

Maintenance—2205 Service
8. Remove one screw from the center front
bottom of the attenuator shield.
9. Remove two screws from the front corners of
the Timebase/Attenuator circuit board and two nuts
from the front corners of the attenuator shield.
10. Remove the attenuator shield by pulling it
back until the shield tab clears the Timebase/
Attenuator ground bracket.
To reinstall the Timebase/Attenuator circuit board
assembly, perform the reverse of the preceding
steps.
Front-Panel Circuit Board
The Front-Panel circuit board can be removed
and reinstalled as follows:
1. Perform the Timebase/Attenuator circuit
board assembly removal procedure.
2. Remove the knobs from the following control
shafts by pulling them straight out from the front
panel:
a. INTENSITY.
b. Channel 1 and Channel 2 POSITION.
c. Horizontal POSITION
e. LEVEL.
3. Turn the instrument on its side (CRT down)
and unsolder the following wire straps and resistors
underneath the instrument, noting their locations for
reinstallation reference:
a. Unsolder the two resistors and bare straps
to the CH 1 OR X and CH 2 OR V connectors and
ground lugs from the Front-Panel circuit board.
b. Unsolder the resistor and ground dtrap to
the EXT IN PUT OR 2 connector ;a nd ground lug
from the Front-Panel circuit board.
4. Turn the instrument over again and unsolder
the Trace Rotation wires (J987) from the Front-
Panel circuit board (note the connection locations
and wire colors for reinstallation reference).
5. Remove the Power Switch extension shaft by
disengaging from power switch and pulling it out
through the Front-Panel circuit board.
6. Disconnect the following six-wire cables from
the front edge of Main circuit board, noting their
locations for reinstallation reference: J1, 42, 43; J5,
and 46.
7. Remove the five screws that secure the
Front-Panel circuit board to the front chassis, noting
their respective positions.
8. Remove the Front-Panel circuit board from
the front chassis taking care not to lose the slider
switch covers.
To reinstall the Front-Panel circuit board, per
form the reverse of the preceding steps.
Main Circuit Board
All components on the Main circuit board are
accessible either directly or by removing either the
crt, Power Transformer or the Timebase/Attenuator
circuit board assembly. Removal of the Main circuit
board is required only when it is necessary to re
place the circuit board with a new one.
The Main circuit board can be removed and re
installed as follows:
1. Perform the Cathode-Ray Tube removal
procedure.
2. Perform step 1 of the Power Transformer
procedure.
3. Unsolder the three-wire cable from the
FOCUS potentiometer. The FOCUS potentiometer is
located on the rear of the inner chassis.
4. Unsolder W893 from the Main circuit board.
The cable is connected to the Focus pot located on
the rear of the inner chassis.
§. Unsolder W903, a three ribbon from the
Mains Input circuit board.
6. Disconnect the following cables from the
Timebase/Attenuator circuit board assembly, noting
their locations for reinstallation reference:
a. 490, a six-wire cable located at the rear
edge of the circuit board.
b. 4755, a four-wire cable located at the rear
right-hand corner of the circuit board.
c. 430, a four-wire cable located to the left of
the CH 1 attenuator switch.
d. 480. a four-wire cable located between
the CH 1 and CH 2 attenuator switches.
e. J7, a six-wire cable located between the
CH 2 attenuator switch and the SEC/DIV switch.
f. 4701, a six-wire cable located at the front
right-hand corner of the circuit board.
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Tektronix 2205 Specifications

General

Brand	Tektronix
Model	2205
Category	Test Equipment
Language	English