Mindray Passport 5-Lead, Service Manual

Page: 282 / 544

Troubleshooting Guidelines Repair Information
4 - 2 0070-00-0420 Passport 5-Lead, 5L, LT, XG Service Manual
4.3 Troubleshooting Guidelines
In an instrument as complex as this, it is virtually impossible to list each and every potential
problem and appropriate action. Any given problem, however, can be effectively identified
through an understanding of the instrument features and the theory of operation. These are
prerequisites for repair. If necessary, read the Operating Instructions Manual and study the
theory of operation presented in Chapter 2.0 of this manual. The time spent reading and
absorbing this information is generally realized by a reduction in repair time and, ultimately,
in the overall experience of service personnel.
NOTE: The numbers in parentheses () refer to the isometric
drawings.
General Troubleshooting Guidelines
1. Identify The Problem . Due to the wide ranges of potential symptoms, certain
problems may be more subtle than others. One approach to trouble-shooting is to set-up
the instrument for testing as described in Chapter 7 and attempt testing. If successful,
there is a reasonable assurance that there is no problem. By contrast, the fact that a
particular test is not successful is generally indicative of a failure in that specific area.
The cause of the symptom can now be further isolated by referring to Chapter 2. Section
2-5 contains a listing of specific circuits or areas in the instrument, each of which is
dedicated to provide a specific function. Once the operation of that circuit is
understood, trouble-shooting can be completed by making measurements in that circuit
to determine which component(s) is at fault.
2. Avoid Shorting Component Leads . During repair procedures, it can become
tempting to make a series of quick measurements. Always turn off the power before
connecting and disconnecting test leads and probes. The accidental shorting of
component leads can easily over stress components, resulting in a second unnecessary
failure (aside from creating a possible safety risk).
3. Use The Proper Equipment . This equipment listed in “Equipment and Special Tools
Required” on page 4-3 is suggested to fulfill a wide range of troubleshooting
requirements. Use a soldering iron the appropriate wattage for a given job. For
example, use a pencil-type iron (25 watts max.) for repairs to printed wiring boards and
a pistol-grip (75 watts) for repairs requiring this much power. Do not use the high
powered iron to repair the printed wiring boards as the conductors will lift from the
board under the extreme heat, thus ruining it.
4. Clean The Repair Area . After soldering operations, clean off the repaired area with
alcohol and a stiff hair brush. This will remove residual solder flux, making the repaired
area more visible for inspection and returning the instrument to its original, neat
appearance. Removal of the flux will also facilitate making electrical measurements in
the affected area.
Exchange Program
Datascope offers an exchange program for certain assemblies in the instrument. In many
cases, replacement of the complete assembly will result in the most expedient repairs. See
“Exchange Program” on page 6-2 for details concerning the exchange program.