Maintenance; Table; Rear Connector Pin Assignments - Tektronix DD 501 Instruction Manual

MAINTENANCE
Section 4
—
DD
501
INTRODUCTION
This section
of
the
manuai contains
maintenance information applicable only
to
the
DD
501.
General system
maintenance procedures are
provided
in
the
Power Module
instruction
manual,
i.e.,
preventive
maintenance,
troubleshooting
aids,
parts
removal
and replacement procedures,
parts
ordering information,
etc.
SERVICES AVAILABLE
Tektronix,
Inc.
provides
complete instrument
repair
and
calibration at local Field
Service Centers
and
at
the
Factory Service Center.
Contact your
local
Tektronix Field
Office or representative for
further information.
FUSE
REPLACEMENT
TABLE
4-1
Fuse Ratings
Circuit
Rating
Function Location
F366
2
A
Fast
+5
Volts
Rear
of
circuit
board
F386
0.5
A
Fast
-15
Volts
Rear
of
circuit
board
SEMICONDUCTOR REPLACEMENT
Periodic
checks
of the
semiconductors
in
the
DD
501
are not
recommended. The
best
check
of
semiconductor
performance
is
actual
operation
in
the
instrument;
however,
if it
should
become
necessary
to
remove
or
replace the input FET's,
Q28A
and
Q28B
for
the events
input,
or
Q128A
and
Q128B
for
the start input,
both
transistors of
the
pair
should be
removed or replaced as a
unit.
More
details
on checking semiconductor
operation are
given
in
the
Power Module
instruction
manual.
TABLE
4-2
Rear Connector
Pin
Assignments
Pin
Number
Left (A)
Right
(B)
14
—
28
Not
asi
signed
12
—
13
See
note
below
11
Base
of
PNP
Series
Pass Collector
of
PNP
Series
Pass
10
Emitter
of
PNP
Series
Pass
9
See
note
below
8
—33.5 V
filtered
dc
-33.5 V
filtered
dc
7
Emitter of
NPN
Series
Pass Collector of
NPN
Series
Pass
6
Base
of
NPN
Series
Pass
5
See note
below
4
+11.5 V
common
return
+11.5
V common
return
3
+11.5
V
common
return
+11.5
V
common
return
2
+11.5
V
filtered
dc
+11.5
V
filtered
dc
1
See
note
below
NOTE: Not used by
the
DD
501.
See
Power Module manual
for
assignments.
REV.
A,
NOV
1975
4-1