Maintenance; Static-Sensitive Components - Tektronix 2205 Service Manual

This section contains information for conducting
preventive maintenance, troubleshooting, and cor-
rective maintenance on the instrument. Circuit

STATIC-SENSITIVE COMPONENTS

The following precautions are applicable when
performing any

maintenance

access to the instrument.
A A A A A A A A
a
i
CAUTION
Static discharge can damage any semi­
conductor component in this instrument.
This instrument contains electrical components
that are susceptible to damage from static dis­
charge. Table 6-1 lists the relative susceptibility of
various classes of semiconductors. Static voltages
of 1 KV to 30 KV are common in unprotected
environments.
When performing maintenance, observe the fol­
lowing precautions to avoid component damage:
1. Minimize handling
components.
2. Transport and store static-sensitive ; com­
ponents or assemblies in their original containers or
on a metal rail. Label any package that contains
static-sensitive components or assemblies.
3. Discharge the static voltage from your body
by wearing a grounded antistatic wrist strap while
handling these components.
sensitive components or assemblies should be
performed only at a static-free work station by
qualified service personnel.
4. Nothing capable of generating or holding a
static charge should be allowed on the work station
surface.
MAINTENANCE
involving internal
m
1
of static-sensitive
Servicing static-
board removal procedures are included in the Cor-
rective Maintenance part of this section,
Table 6-1
Relative Susceptibility to Static-Discharge
D a m a g e ..........
Semiconductor Classes
MOS or CMOS microcircuits or
discretes, or linear microcircuits
with MOS inputs (Most Sensi­
tive)
ECL .
Schottky signal diodes
Schottky TTL
High-frequency bipolar
transistors
JFET
Linear microcircuits
Low-power Schottky TTL
TTL (Least Sensitive)
aVoltage equivalent ter levels (voltage discharged
from a 100-pF capacitor through a resistance of
100 P'J1
= 100 to 500 V
1
2 a 200 to 500 V
3 * 250 V
4 500 V
3
5 400 to 600 V
3
5. Keep the component leads shorted together
whenever possible.
6. Pick up components by their bodies, never
by their leads.
Section 6—2205 Service
Relative-
Susceptibility
Levels®
1
2
3
4
5
6
7
8
■ : 9
= 600 to 800 V
6
7 = 400 to 1000 V (est)
s 900 V
8
9 * 1200 V
6-1