Tektronix T921 User Manual

Replacement Parts
(1) Instrument type .
NOTE
If the instrument does not work after replacing
components by soldering to the leads of the
previous one, the connection
with the etched circuit
wiring may be broken . To check the connections, it
is necessary to remove the circuit board from the
instrument . Refer to the circuit board replacement
information .
All parts for the T921 /T922/T922R can be ordered from
your local Tektronix Field Office, but many of the com-
ponents are standard items that may be more readily
available locally . Check the Parts Lists for value,
tolerance, ratings, and description before you replace any
components .
When ordering parts from Tektronix, include the
following information :
(2) Instrument serial number .
(3) A description of part (if electrical, include the
circuit number) .
(4) Tektronix part number .
COMPONENT REPLACEMENT (T921 and T922)
NOTE
Refer to the end of this section for component
replacement information for the T922R .
WARNING
Disconnect the power cord plug from the power
input source before replacing components .
Since
the components are located on one side of the
circuit boards, it may be
necessary to remove the circuit
boards before replacing some components
. Refer to the
part on circuit board replacement for instructions on
removal and installation of each circuit board . Also be sure
you're familiar with soldering techniques usedon single-
sided circuit
boards .
REV . C APR 1977
Semiconductdrs
Service
Information-T921/T922/T922R
Replacement
of semiconductors may affect the adjust-
ment of this instrument . After
replacing semiconductors,
especially if using parts other than those listed
in the parts
list,
check the performance of the instrument to be
sure
that the performance has
not been degraded .
WARNING
Handle silicone grease with care . Avoid getting
silicone grease in the eyes . Wash hands thoroughly
after use .
Replacement semiconductors should be of the original
type
or
a
direct replacement . Lead configuration of the
semiconductors used in
this instrument are shown at the
beginning of the corrective maintenance
section . Some
plastic case transistors have lead configurations which
do
not agree with those shown there . If a replacement
transistor is made by a different manufacturer than the
original, check the
manufacturer's basing diagram for
correct basing . Most
transistors are soldered directly onto
the circuit boards . Transistors having
heat radiators or
those mounted on the chassis use silicone
grease to
increase heat transfer . Replace the
silicone grease when
replacing these transistors . Those transistors
mounted on
the
chassis are held in place by a metal clip .
Fuse
Replacement
NOTE
After replacing
a power transistor, check that the
collector is not
shorted to ground before applying
power .
Power Cord Conductor Identification
The line-voltage fuse, F700, is located next to the
POWER
ON
switch,
S700, on the Interface board . The high
voltage fuse, F722, is located
on the Power Supply board .
Refer to the Electrical Parts
List
for
correct fuse values .
Thick Film Resistor Replacement
To remove the thick film resistors, first remove the
solder from the pins and
then remove the resistors .
To
replace the thick
film resistor, R118, match the
triangles-one on the resistor and one
on
the circuit
board . Resolder all of the pins to the circuit board . To
replace the thick film resistor, R444, match the pins on the
resistor with the holes in the circuit board . Re-solder all of
the pins to the circuit board .
5- 1 1
Conductor
Color Alternate Color
Ungrounded (Line) Brown Black
Grounded (Neutral) Blue White
Grounding (Earthin g) Green-Yellow Gree n-Yellow

Tektronix T921 Specifications

General

Brand	Tektronix
Model	T921
Category	Test Equipment
Language	English