Lenovo ThinkStation P520 User Manual page 16

2 Signal diagnostic LED indicator
Off (when the computer is powered on): No error or issue is detected on your computer during normal
operation.
On: A catastrophic error is detected on your computer during normal operation.
Blinking: An error or issue is detected on your computer during normal operation.
3 Power button
Press the power button to turn on your computer. If your computer is unresponsive, you can turn off the
computer by pressing and holding the power button for four or more seconds.
4 Power indicator
When the power indicator is on, the computer is turned on.
5
Storage drive activity indicator
This indicator shows the status of the internal storage drives (such as hard disk drives or solid-state drives).
On: The storage drives are active and data is being transferred.
Off (when the computer is powered on): No data is being transferred or the storage drives are not in use.
6
Photoelectric sensor
This sensor receives the flash light sent by the Lenovo PC Diagnostics application installed in the
smartphone. Then, the photoelectric sensor triggers the computer to send the tune of the detected error to
the smartphone for users to decode the error.
7 Headset connector
Use this connector to attach a headset to your computer.
8 USB 3.0 connector (4)
Use this connector to attach a USB-compatible device, such as a USB keyboard, mouse, storage drive, or
printer.
9 SD card slot
Insert a secure digital (SD) card into the slot to access the data on the card.
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P520 User Guide