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Dell PowerEdge 2650
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Dell PowerEdge 2650

SCSI Backplane

The PowerEdge 2650 backplane main board, shown below, incorporates the following features:
  • Five hot-plug-capable Ultra-160 LVD SCSI slots (upgradeable to Ultra-320 LVD SCSI when available) with two LED indicators per slot
  • Two 68-pin SCSI connectors for connecting add-in LVD SCSI controllers to the backplane
  • A set of quick-switches for splitting the SCSI bus
  • One slot for connecting a daughter board to the backplane.
All voltages, temperatures, and fan speeds are captured via LM81 and LM75 chips.

IMPORTANT - More Information   NOTE: The drive ordering below is done from left to right, bottom to top.

Click on the image below to view the front and rear photos.

This is a picture of the SCSI backplane, viewed from the front. Click on this picture to flip the image

Cableless Backplane

The PowerEdge 2650 is the first server to offer a cableless backplane option. In lieu of cables, the SCSI bus is routed through the system board directly to the backplane. The elimination of internal SCSI cables will promote better airflow in the system and reduce the time required to service the system board or backplane.

The cableless design does not support routing one of the internal SCSI channels externally, because it is not possible to route the SCSI signals on the system board in a way that would provide the option to choose an internal or an external connection for the second channel. Given this design limitation, the option for two internal channels using the embedded controller was preferable to the ability to route the internal controller externally.

You'll notice the lack of SCSI cables immediately "out of the box". To reseat the backplane the first option is to reseat the processor board to the backplane. There is one cable, from the Control Panel to the backplane located on the right of the server as it faces you. A picture is provided below.

This is a picture of the PowerEdge 2650 backplane subsystem

IMPORTANT - More Information   NOTE: Although the 2650 backplane is "cableless" if a expansion SCSI or RAID card is included in the system, the internal hard drives will be attached via a cable (or cables) to connectors on the backplane. Please see the picture below for more information.

This is a picture of the PowerEdge 2650 backplane subsystem with the channels highlighted

Splitting the backplane
The PowerEdge 2650 supports two types of hot-plug capable SCSI backplane configurations. Each configuration supports 1.0" drives only. The backplane can be split to support duplexed configurations when a single daughter board is installed (shown below).

The daughter board is required because it includes a second enclosure management chip implementing the SAF-TE specification to support "hot-plugging" of hard drives.

 This image shows the PowerEdge 2650 with the cover open and the daughter board location highlighted

The image below shows a close-up of the daughter board. You can click on the image to flip between the top view and the bottom view.
This image shows the SCSI daughter board from the top view. Click on this picture to flip the image

The following configurations are available:

  • Active 1 x 5: one channel with a maximum of five 1.0" drives, hot-plug support
  • Active Split 5: two channels (1x2 and 1x3) with maximum of five 1.0" drives, hot-plug support

This is a picture of the configurations available for the SCSI backplane (one channel with five 1.0 drives or two channels with five 1.0 drives)

SCSI backplane removal

To remove the SCSI backplane, follow the steps below:

 Removing the Backplane

Step 1: Perform the following steps prior to removing the backplane:
  • Remove the front bezel.
  • Remove the system cover.
  • Remove the hard-disk drives.
  • Remove the floppy-diskette/CD/DVD-ROM drive assembly.
  • Remove the control panel cable cover.
  • Remove the split backplane card(if applicable).
  • Remove the system board tray.
This is a picture of the PowerEdge 2650 backplane subsystem

Step 2: Disconnect the control panel cable from the backplane board.

Step 3: Loosen the thumbscrew that secures the backplane board in the system.
This is a picture of the PowerEdge 2650 backplane subsystem with the thumbscrew highlighted

Step 4: Facing the back of the system chassis, slide the backplane board toward the left side chassis wall.
This picture illustrates how to slide the backplane board toward the left side chassis wall.

Step 5: Lift the backplane board off of its grounding tabs and out of the system board tray.
This is a picture of how to lift the backplane board off of its grounding tabs and out of the system board tray.

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