Tektronix 1740A Series, Руководство пользователя

Страница: 172 / 368

Maintenance
1740A/1750A/1760 – Series Service Manual
6–5
1. Ensure that the malfunction exists in the instrument. This is done by
making sure that the instrument is operating as intended by Tektronix (see
Operating Instructions), and by checking that a malfunction has not occurred
up stream from the waveform monitor.
2. Determine and evaluate all trouble symptoms. This is accomplished by
isolating the problem to a general area such as an assembly. The block
diagram is a valuable aid in signal tracing and circuit isolation.
CAUTION.
Use extreme care when probing with meter leads or probes, because
of the high component density and limited access within the instrument. The
inadvertent movement of leads or a probe could cause a short circuit or
transient voltages capable of destroying components.
3. Determine the nature of the problem. Attempt to make the determina-
tion of whether the instrument is out of calibration or if there has been a
component failure. Once the type of failure has been determined, proceed on
to identify the functional area most likely at fault.
4. Visually inspect the suspect assembly for obvious defects. Most
commonly these will be broken or loose components, improperly seated
components, overheated or burned components, chafed insulation, etc.
Repair or replace all obvious defects.
5. Use successive electrical checks to locate the source of the problem. The
primary tool for problem isolation is the oscilloscope. Use the Performance
Check Procedure to determine if a circuit is operating within specifications.
At times it may be necessary to change a calibration adjustment to determine
if a circuit is operational, but since this can destroy instrument calibration,
care should be exercised. Before changing an adjustment, note its position
so that it can be returned to its original setting.
6. Determine the extent of the repair. If the necessary repair is complex, it
may be advisable to contact your local Tektronix field office or representa-
tive before continuing. If the repair is minor, such as replacing a component,
see the parts list for replacement information. Removal and replacement
procedures for the assemblies can be found under Corrective Maintenance.
CAUTION.
Always remove the assembly from the instrument prior to attempting
to replace a solderedĆin component. See Corrective Maintenance for the correct
procedure.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com