Lenovo ThinkSystem SR850 V2 Maintenance Manual page 186

The power-control button on the device and the power switch on the power supply do not turn off the
electrical current supplied to the device. The device also might have more than one power cord. To
remove all electrical current from the device, ensure that all power cords are disconnected from the
power source.
Attention:
• Read "Installation Guidelines" on page 107 to ensure that you work safely.
• Power off the server and disconnect all power cords for this task.
• Prevent exposure to static electricity, which might lead to system halt and loss of data, by keeping static-
sensitive components in their static-protective packages until installation, and handling these devices with
an electrostatic-discharge wrist strap or other grounding system.
• If the server is in a rack, remove it from the rack.
• Each processor socket must always contain a cover or a PHM. When removing or installing a PHM,
protect empty processor sockets with a cover.
• Do not touch the processor socket or processor contacts. Processor-socket contacts are very fragile and
easily damaged. Contaminants on the processor contacts, such as oil from your skin, can cause
connection failures.
• Do not allow the thermal grease on the processor or heat sink to come in contact with anything. Contact
with any surface can compromise the thermal grease, rendering it ineffective. Thermal grease can damage
components, such as the electrical connectors in the processor socket.
• Remove and install only one PHM at a time. If the system board supports multiple processors, install the
PHMs starting with the first processor socket.
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