Beforeyou Start; Troubleshooting; Fuse Blows, No Dial Lamp - Wavetek 193 Instruction Manual

6-1
6.3.1 Fuse Blows, No Dial Lamp
1. Fuse size incorrect for voltage setting.
2. Line voltage selector incorrectly positioned.
6.3.12
6.3.13
6.3.11
6.3.9
6.3.10
6.3.8
6.3.4
6.3.5
6.3.6
6.3.7
6.3.3
6.3.1
6.3.2
Fuse blows, no dial lamp.
Power supply
>
100 mVp-p ripple or out of
specification.
Function out (all functions) distorted or
missing.
Square output distorted or rnisslnq.
Sine wave output distorted or missing.
Triangle output distorted or missing.
Sync output distorted or missing (FUNC OUT
normal).
Excessive high frequency sine or triangle
roll off, excessive square wave overshoot and
rise/fall time.
Low frequency square wave tilt.
Time symmetry cannot be adjusted within
specification.
Frequency accuracy and FREQ/STARTFREQ
dial response problems.
Trigger, gate and trigger baseline problems.
Voltage at VCG IN connector not changing
frequency properly.
DC offset not functioning correctly.
Variable symmetry problems
Paragraph
6.3.14
6.3.15
Symptom
Table 6·1. Generator Board Related Problems
paragraph 5.2 and circuit schematics are in the back
of this manual.
In all problems:
1. Double check for proper control settings.
2. Calibrate or rule out calibration as a problem.
3. Inspect components, wiring and circuit boards for
heat damage.
4. Recalibrate as necessary after circuit repair.
Find the instrument symptom in table 6-1 and proceed
as directed to the proper troubleshooting paragraph.
See paragraph 6.5 for sweep/mod board related
problems.
SECTION
6
TROUBLESHOOTING
Table 6-1 gives an index of common generator board
symptoms. For each symptom a troubleshooting
guide is referenced (Paragraphs 6.3.1 through 6.3.15)
that, when correctly followed, will lead to a solution to
the problem.
The troubleshooting guide is arranged in three (3)
levels:
1. Identify improperly set controls.
2. Isolate the faulty functional blocks.
3. Identify the faulty circuit or component.
Individual component troubleshooting is given in para-
graph 6.7, recommended test equipment is given in
WARNING
With the covers removed, dangerous
voltage polnts may be exposed. Contact
with any of these points could cause
serious injury or death.
6.3 GENERATOR BOARD TROUBLESHOOTING
6.2 BEFORE YOU START
Since no troubleshooting guide can possibly cover all
the potential problems, the aim of this guide is to give
a methodology which, if applied consistently, will lead
to the problem area. Therefore, it is necessary to
familiarize yourself with the instrument by reviewing
the functional description and the detailed circuit
description in conjunction with the schematic. Suc-
cessful troubleshooting depends upon understanding
the circuit operation within each functional block as
well as the block relationships.
For sweep/mod board problems, refer to paragraph
6.5. For all other problems, refer to paragraph 6.3.
6.1 FACTORY REPAIR
Wavetek maintains a factory repair department for
those customers not possessing the necessary per-
sonnel or test equipment to maintain the instrument. If
an instrument is returned to the factory for calibration
or repair, a detailed description of the specific prob-
lem should be attached to minimize turnaround time.