Electrostatic Discharge Information; Hazards Of Internal Repair And Adjustment - HP 70001A Installation And Veri Cation Manual

Electrostatic Discharge Information

Electrostatic discharge (ESD) can damage or destroy electronic components. All work on
electronic assemblies should be performed at a static-safe work station. Figure 1-2 shows an
example of a static-safe work station using two types of ESD protection: (1) wrist-strap (with
greater than 1m isolation to ground) and table-mat combination, (2) heel-strap (with greater
than 1m isolation to ground) and conductive oor-mat combination. The two types must
be used together to ensure adequate ESD protection. Isolation to ground must be provided
for personnel protection. Refer to Table 1-3 for a list of static-safe accessories and their part
numbers.
WARNING
In order to provide proper personnel protection, the wrist- and
heel-straps must have greater than 1mohm isolation to ground.

Hazards of Internal Repair and Adjustment

If the HP 70001A bottom cover is removed for any reason, the following precautions must be
observed.
WARNING
Disassembly, adjustments, and internal repairs should only be attempted
by quali ed technical personnel.
The mainframe internal power supplies have lethal voltages, with lethal
currents, in all areas.
DANGEROUS VOLTAGES exist on boards in this instrument even when the
power is o .
Board assembly voltages cannot be safely measured without an isolation
transformer.
AC power line voltage is present on the power supply board, even when
the power switch is o .
The power supply board circuit common can be at approximately 200 V,
not earth ground.
Capacitors may retain high-voltage stored charges for several minutes,
even with no power applied.
1-8 General Information