Lake Shore 460, User Manual

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Lake Shore Model 460 Gaussmeter User’s Manual
Service
6-1
CHAPTER 6
SERVICE
6.0 GENERAL
This chapter covers general maintenance precautions in Paragraph 6.1, electrostatic discharge in
Paragraph 6.2, line voltage selection in Paragraph 6.3, fuse replacement in Paragraph 6.4, rear panel
connector definitions in Paragraph 6.5, optional serial interface cable and adapters in Paragraph 6.6,
operating software EPROM replacement in Paragraph 6.7, and error messages in Paragraph 6.8.
There are no field serviceable parts inside the Model 460. Contact Lake Shore about specific problems
with the Model 460.
6.1 GENERAL MAINTENANCE PRECAUTIONS
The following are general safety precautions unrelated to any other procedure in this publication. Keep
away from live circuits. Installation personnel shall observe all safety regulations at all times. Turn off
system power before making or breaking electrical connections. Regard any exposed connector,
terminal board, or circuit board as a possible shock hazard. Discharge charged components only when
such grounding results in no equipment damage. If a test connection to energized equipment is
required, make the test equipment ground connection before probing the voltage or signal to be tested.
Do not install or service equipment alone. Do not reach into or adjust the equipment without having
another person nearby capable of rendering aid.
If there is no power, verify the power cord is plugged into a live outlet and that both ends are securely
plugged in. Next, check the fuse (refer to Paragraph 6.4).
Use this procedure to periodically clean the instrument to remove dust, grease, and other contaminants:
1. Clean front and back panels and case with soft cloth dampened with a mild detergent and water
solution.
NOTE : Do not use aromatic hydrocarbons or chlorinated solvents to clean the instrument. They may
react with the plastic materials used in the case or the silk screen printing on the back panel.
2. Clean the surface of printed circuit boards (PCBs) with clean, dry air at low pressure.
6.2 ELECTROSTATIC DISCHARGE
Electrostatic Discharge (ESD) may damage electronic parts, assemblies, and equipment. ESD is a
transfer of electrostatic charge between bodies at different electrostatic potentials caused by direct
contact or induced by an electrostatic field. The low-energy source that most commonly destroys
Electrostatic Discharge Sensitive (ESDS) devices is the human body, which generates and retains
static electricity. Simply walking across a carpet in low humidity may generate up to 35,000 volts of
static electricity.
Current technology trends toward greater complexity, increased packaging density, and thinner
dielectrics between active elements, which results in electronic devices with even more ESD sensitivity.
Some electronic parts are more ESDS than others. ESD levels of only a few hundred volts may
damage electronic components such as semiconductors, thick and thin film resistors, and piezoelectric
crystals during testing, handling, repair, or assembly. Discharge voltages below 4000 volts cannot be
seen, felt, or heard.