Keithley 7035, Инструкция по эксплуатации

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5
Service Information
5-1
WARNING
The information in this section is
intended only for qualified service per-
sonnel. Some of the procedures may
expose you to hazardous voltages that
could result in personal injury or death.
Do not attempt to perform these proce-
dures unless you are qualified to do so.
Introduction
This section contains information necessary to service the
Model 7035 multiplexer card and is arranged as follows:
• Handling and cleaning precautions — Discusses han-
dling precautions and methods to clean the card should
it become contaminated.
• Performance verification — Covers the procedures
necessary to determine if the multiplexer card meets
stated specifications.
• Special handling of static-sensitive devices —
Reviews precautions necessary when handling static-
sensitive devices.
• Principles of operation — Briefly discusses circuit
operation.
• Troubleshooting — Presents some troubleshooting tips
for the Model 7035 including relay replacement precau-
tions.
Handling and cleaning precautions
Because of the high-impedance areas on the Model 7035,
care should be taken when handling or servicing the card to
prevent possible contamination. The following precautions
should be taken when handling the card.
Handle the card only by the edges and shields. Do not touch
any board surfaces, connectors, or components not associ-
ated with the repair. Do not touch areas adjacent to electrical
contacts. When servicing the card, wear clean cotton gloves.
Do not store or operate the card in an environment where
dust could settle on the circuit board. Use dry nitrogen gas to
clean dust off the board if necessary.
Should it become necessary to use solder on the circuit
board, use an OA-based (organic activated) flux. Remove the
flux from the work areas when the repair has been com-
pleted. Use pure water along with clean cotton swabs or a
clean soft brush to remove the flux. Take care not to spread
the flux to other areas of the circuit board. Once the flux has
been removed, swab only the repaired area with methanol,
and then blowdry the board with dry nitrogen gas.
After cleaning, the card should be placed in a 50
°
C low
humidity environment for several hours before use.