Troubleshooting; Before You Start; Safety; Required Tools - Wyse WY-120 Maintenance Manual

2
BEFORE YOU START
Safety
Required Tools
Troubleshooting
Read the following safety information carefully before you attempt
to troubleshoot your unit.
This terminal contains high voltage. Don't attempt to service the
terminal without taking the following precautions:
• Turn the terminal off and disconnect the power cable.
• Remove jewelry from your hands and wrists.
• Avoid wearing clothing made of synthetic fabrics.
• Use insulated or nonconductive tools.
• Handle circuit boards only by their edges.
• Don't reconnect the power cable or turn the terminal on
unnecessarily while the terminal enclosure is removed.
• Whenever you connect or disconnect the anode from the
anode lead, make sure to discharge the anode as directed in
Section 1.
&
Warning The CRT/yoke assembly has high voltages. Only
qualified service personnel should adjust it.
• If you need to remove or replace the CRT/yoke assembly,
remember that it can implode if you drop it or break the neck.
The flying glass can injure anyone within a radius of ten feet.
• Always use the manufacturer's replacement components.
Especially critical components as indicated on the circuit
schematics should not be replaced with any component other
than the manufacturer's. Where a short circuit has occurred,
replace those components that indicate evidence of overheating.
Before you start to repair the terminal, make sure you have the
following tools and materials:
• No. 2 Phillips screwdriver
• 3/16-inch flat-blade screwdriver
• Digital multimeter (DMM) or a voltmeter
• Test connectors for the MAIN and AUXl ports
• Nonconductive video alignment tool
• 100-MHz oscilloscope