Control Data Corporation CYBER 180 810 Maintenance And Parts Manual page 95

FIELD REMOVAL AND REPLACEMENT
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Field removal and replacement proc~dures are for equipment subassemblies and
components that might cause personnel hazards, equipment damage, or procedural
problems. It is important that you read the removal and replacement steps to
gain familiarity with the procedure and determine the need for special tools,
test equipment, and parts. It is also important that you conduct proper
electrostatic discharge control in handling any components.
ELECTROSTATIC DISCHARGE (ESD) CONTROL
The computer contains many semi-conductor components that are highly sensitive
to electrostatic discharge (ESD). For control of ESD, any assembly containing
an IC (integrated circuit) should be handled using the following techniques.
GUIDELINES FOR HANDLING INTEGRATED CIRCUITS
1. Do not remove an assembly, subassembly, part, component, or pak from its
static-shielded bag unless you are at a static-protected workstation and
you are wearing a properly grounded wrist strap.
2. Handle assemblies by edges of board; do not touch connectors or components.
3. Turn power off before removing or installing an ESD sensitive assembly
from any part of a computer system.
4. Put on a properly grounded wrist strap before removing any ESD sensitive
assembly. A properly grounded wrist strap is one that is grounded to the
·chassis of the equipment you are working on.
5. Place an assembly in a static-shielded bag immediately after removing it
for repair. It is important that you do so before it is laid asside and
while you still have your wrist strap connected.
6. If you are going to-use any test device on an ESD sensitive assembly,
touch the leads of the test device to the unit ground before starting.
7. If you received an assembly in a static-shielded bag, replace it in a
static-shielded bag before returning it.
8. Test your wrist strap monthly with an ohmmeter as follows:
1) Measure resistance between the banana plug and the metal strip on the
inside of the wrist strap band. (The wrist strap contains a lM ohm
resistor for current limiting and user safety.)
2) If the reading is not between 870 K ohms and 1.5 M ohms, discard the
strap and get a new one.
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