Tektronix 485, Instruction Manual

Page: 39 / 197

Maintenance-485/R485 Service
.5 V /D IV
N.) AC coupled at TP1665. Normal operation with inten­
sity off.
20 psec/DIV
|5 0 V /D IV
■+150 V
|2 0 usec/DI V
O.) X10 Probe at Anode of CR1656 Normal operation with
intensity off.
1 V /D IV
P.l AC coupled at TP 1653. Normal operation with inten­
sity off.
20 psec/DIV
Fig. 4-2. Power Supply Waveforms cont.
C O R R E C T IV E M A IN T E N A N C E
General
Corrective maintenance consists of component
replacement and instrument repair. Special techniques
required to replace components in this instrument are given
here.
If any defective parts are located, follow the replacement
procedures given in this section. Be sure to check the
performance of any circuit that has been repaired or that
has had any electrical components replaced.
Obtaining Replacement Parts
Standard Parts. A ll electrical and mechanical part
replacements for the 485 can be obtained through your
local Tektronix Field Office or representative. However,
many of the standard electronic components can be
obtained locally in less time than is required to order them
from Tektronix, Inc. Before purchasing or ordering
replacement parts, check the parts lists for value, tolerance,
rating, and description.
NOTE
When selecting replacement parts, i t is im p o rta n t to
remember th a t the physical size and shape o f a
com ponent may a ffe ct its performance in the
instrum ent, pa rticu la rly a t high frequencies. A ll
replacement parts should be d ire ct replacements
unless i t is know n th a t a d iffe re n t com ponent w ill n o t
adversely a ffe c t instrum ent performance.
Special Parts. In addition to the standard electronic
components, some special components are used in the 485.
These components are manufactured or selected by
Tektronix, Inc. to meet specific performance requirements,
or are manufactured for Tektronix, Inc. in accordance with
our specifications. Most of the mechanical parts used in this
instrument have been manufactured by Tektronix, Inc.
Order all special parts directly from your local Tektronix
Field Office or representative.
Ordering Parts. When ordering replacement parts from
Tektronix, Inc., include the following information:
1. Instrument type.
2. Instrument serial number.
3. A description of the part (if electrical, include circuit
number).
4. Tektronix Part Number.
Soldering Techniques
W A R N I N G
Disconnect the instrum ent from the power source
before soldering.
®
REV. APR 1974
4-11