Lenovo 7099U1U, Hardware Maintenance Manual

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Voltage-selection switch
Some computers are equipped with a voltage-selection switch located near the power-cord connection
point on the computer. If your computer has a voltage-selection switch, ensure that you set the switch to
match the voltage available at your electrical outlet. Setting the voltage-selection switch incorrectly can
cause permanent damage to the computer.
If your computer does not have a voltage-selection switch, your computer is designed to operate only at the
voltage provided in the country or region where the computer was originally purchased.
If you relocate your computer to another country, be aware of the following:
• If your computer does not have a voltage-selection switch, do not connect the computer to an electrical
outlet until you have verified that the voltage provided is the same as it was in the country or region
where the computer was originally purchased.
• If your computer has a voltage-selection switch, do not connect the computer to an electrical outlet until
you have verified that the voltage-selection switch is set to match the voltage provided in that country
or region.
If you are not sure of the voltage provided at your electrical outlet, contact your local electric company or
refer to official Web sites or other literature for travelers to the country or region where you are located.
Safety inspection guide
The intent of this inspection guide is to assist you in identifying potentially unsafe conditions on these
products. Each machine, as it was designed and built, had required safety items installed to protect users
and service personnel from injury. This guide addresses only those items. However, good judgment should
be used to identify potential safety hazards due to attachment of features or options not covered by this
inspection guide.
If any unsafe conditions are present, you must determine how serious the apparent hazard could be and
whether you can continue without first correcting the problem.
Consider these conditions and the safety hazards they present:
• Electrical hazards, especially primary power (primary voltage on the frame can cause serious or fatal
electrical shock).
• Explosive hazards, such as a damaged CRT face or bulging capacitor
• Mechanical hazards, such as loose or missing hardware
The guide consists of a series of steps presented in a checklist. Begin the checks with the power off, and
the power cord disconnected.
Checklist:
1. Check exterior covers for damage (loose, broken, or sharp edges).
2. Power-off the computer. Disconnect the power cord.
3. Check the power cord for:
a. A third-wire ground connector in good condition. Use a meter to measure third-wire ground continuity
for 0.1 ohm or less between the external ground pin and frame ground.
b. The power cord should be the appropriate type as specified in the parts listings.
c. Insulation must not be frayed or worn.
4. Remove the cover.
Chapter 2
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Safety information
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