Tektronix T921 Instruction Manual page 77

SHORT METAL CONTACT
(INSIDE BOOT) TO 3/16
INCH POST
7 . Remove crt socket .
SHORT OUTPUT OF
HIGH VOLTAGE MULTIPLIER
TO CHASSIS WITH A
PIECE OF INSULATED WIRE
Fig . 5-12. T922R interface board replacement .
REMOVE 3 PLASTIC
SCREWS FROM TRAN-
SISTORS, DURING AS-
SEMBLY, CHECK FOR
A SHORT FROM THE
METAL TAB ON THE
TRANSISTOR TO THE
CHASSIS. IF SHORTED
THE POWER FUSE WILL
BLOW.
OUTPUT OF
HIGH-VOLTAGE
MULTIPLIER
1982-58
8 . Make note of their location to aid reassembly, then
disconnect all harmonica and molex connectors from the
interface board . Don't forget to disconnect the vertical crt
leads and quide them through the holes in the interface
board .
9 . Remove the screws and posts from the interface
board (see Fig . 5-12) .
10 . Lift the interface board out of the instrument .
11 . During reassembly, use the plastic screws to hold
the power transistors (see Fig . 5-12) .
Power Module Replacement
1 . Remove the plastic shield covering the power
module .
Service Information-T921/T922/T922R
2 . Remove P7 from the power module .
3 . Remove two screws and two bolts from the power
module (see Fig. 5-13).
4 . Lift the power module away from the instrument .
Buffer Board Replacement
1 . To aid in reassembly, make note of the positions of
the harmonica connectors on the buffer board . Then,
disconnect the harmonica connectors from the buffer
board .
2 . Remove the four screws from the buffer board.
CRT Replacement
NOTE
You don't need to remove the switch extensions to
remove the buffer board.
3 . Slide the buffer board toward the rear of the
instrument to remove .
1 . Remove the four screws from the left side rail and
remove the side rail .
2. Remove the four screws from the high-voltage shield
and lift the shield away from the instrument .
THESE SCREWS HOLD
TRANSFORMER TO
BOARD . N O NEED TO
LOOSEN THEM-
Fig . 5-13. T922R power module replacement.
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