Service manual

14
Table 3-1 Test Equipment Required for Troubleshooting
Type Purpose Recommend Model
GPIB Controller Communicate with the load via the GPIB HP9825, Series 85, Series 200/300
Signature Analyzer Test most of the primary and secondary circuits Agilent 5005A/B
Digital Voltmeter Check various voltage levels Agilent 3456A
Power Source Provide required input, bias GPIB Board Agilent 6032A
Logic Probe Check data bus lines Agilent 545A
Oscilloscope Check waveforms and signal levels Agilent 1741A
Clip Leads Connect IC pins together AP Products Model LTC
• Work only at static-free workstations. These workstations should include special conductive work surfaces (such as a
table mat, part number 9300-0797) grounded through a one-megohm resistor. Note that metal table tops and highly
conductive carbon-impregnated plastic surfaces are too conductive; they can act as large capacitors and shunt charges
too quickly. The work surface should have distributed resistance of between 10
6
and 10
12
ohms per square.
• While working with equipment on which no point exceeds 500 volts, use a conductive wrist strap in contact with skin.
The wrist strap should be connected to ground through a one-megohm resistor. A wrist strap with insulated cord and
built-in resistor is recommended, such as 3M Co. number 1066 (part numbers 9300-0969 [small] and 9300-0970 [large]
).
• Ground all conductive equipment or devices that may come in contact with static-sensitive components or assemblies
containing them.
• All grounding (device being repaired, test equipment, soldering iron, work surface, wrist strap, etc) should be done to a
single, common ground.
• Where direct grounding of objects in the work area is impractical, a static neutralizer should be used (ionized-air
blower directed at work). Note that this method is considerably less effective than direct grounding and provides less
protection for static-sensitive devices.
• Always store or transport static-sensitive devices (all semiconductors and thin-film devices) in conductive material.
Attach warning labels to the container or bag enclosing the device.
• Always turn power off before removing or installing printed-circuit boards.
• Low-impedance test equipment (signal generators, logic pulsers, etc) should be connected to static-sensitive inputs only
while the components are powered.
• Use a metalized solder-removing tool (solder sucker) such as part number 8690-0227.
• Use a mildly activated rosin core solder (such as Alpha Metal Reliacore number 1, part number 8090-0098) for repair.
The flux residue of this type of solder can be left on the printed-circuit board. Generally, it is safer not to clean the
board after repair. Do not use Freon or other types of spray cleaners. If necessary, the board can brushed using a
natural-bristle brush only. Do not use nylon-bristle or other synthetic-bristle brushes. Do not use high-velocity air
blowers (unless ionized).