Rear View Leds - Lenovo ThinkSystem SR635 Maintenance Manual

On each power supply, there are three status LEDs near the power cord connector. For information about
the LEDs, see "Rear view LEDs" on page 20.
• NMI button
Press this button to force a nonmaskable interrupt (NMI) to the processor. By this way, you can make the
operating system halt (such as Windows Blue Screen of Death) and take a memory dump. You might have
to use a pen or the end of a straightened paper clip to press the button.
• Serial port
Used to connect to the host system serial interface.
• USB 3.2 Gen 1 (5 Gbps) connectors (2)
Used to attach a device that requires a USB 2.0 or 3.1 connection, such as a USB keyboard, USB mouse,
or USB storage device.
• VGA connector
Used to attach a high-performance monitor, a direct-drive monitor, or other devices that use a VGA
connector.
• BMC management network connector
Used to attach an Ethernet cable to manage the baseboard management controller (BMC).
• Ethernet connectors on OCP 3.0 Ethernet adapter (optional)
The OCP 3.0 Ethernet adapter provides two or four extra Ethernet connectors for network connections.
One of the Ethernet connectors on the OCP 3.0 Ethernet adapter can also function as a management
connector using the shared management capacity. If the shared management connector fails, traffic can
automatically switch over to another connector on the adapter.

Rear view LEDs

The rear of the server provides system ID LED, system error LED, Ethernet LEDs, and power supply LEDs.
The following illustration shows the LEDs on the rear view of server model with two PCIe slots. The LEDs on
the rear view of other server models are the same.
Figure 14. Rear view LEDs
Table 11. LEDs on the rear view of the server
Ethernet link LED
1
Power input LED
3
Power supply error LED
5
System error LED
7
1 Ethernet link LED
2 Ethernet activity LED
The BMC network connector has two status LEDs.
ThinkSystem SR635 Maintenance Manual
20
Ethernet activity LED
2
Power output LED
4
System ID LED
6