Table of Contents
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4-14
Service Information
Troubleshooting procedure
Table 4-3
and component layout drawings at the end of
WARNING
CAUTION
NOTE
Table 4-3
Troubleshooting procedure
Step
1
2
3
4
5
6
summarizes scanner card troubleshooting steps. Refer to the schematic diagram
Lethal voltages are present within the Model 2000. Some of the procedures
may expose you to hazardous voltages. Observe standard safety precautions
for dealing with live circuits. Failure to do so could result in personal injury
or death.
Use care when removing relays from the PC board to avoid pulling traces
away from the circuit board. Before attempting to remove a relay, use an
appropriate de-soldering tool, such as a solder sucker, to clear each mounting
hole completely free of solder. Each relay pin must be free to move in its
mounting hole before removal. Also, make certain that no burrs are present
on the ends of the relay pins.
To avoid contamination, which could degrade card performance, always handle the
card only by the side edges and covers. Do not touch edge connectors, board surfaces,
or components on the card. Also, do not touch areas adjacent to electrical contacts
on connectors.
Item/component
Digital ground P1034,
pin 1, 3, 5
P1034, pin 9
U101, pin 2
U101, pin 3
U101, pin 7
U101-U103, pins 10-18
Section 5
for component locations.
Required condition
Comments
All voltages referenced to digital
ground.
+5VDC
Card power supply voltage.
CLOCK pulses
Serial clock pulses.
DATA pulses
Serial data pulses.
STROBE pulse
End of relay update sequence.
Low when relay state
High when relay is not changing
is changed.
state. Relay driver outputs.
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Table of Contents
Troubleshooting
