SCSI Channel MAP 59
6-00020-02
SNC 5100
Testing SCSI Cables
If the cables of the devices attached to a channel have a compatible pinout on
both sides, the SNC 5100 can test the cable using the loop back test.
Step 1. Stop all I/O to the SNC 5100.
Step 2. If the SNC 5100’s command prompt on the terminal is not
diagmode > place the SNC 5100 in diagnostic mode
For more information, see “Entering Diagnostic Mode” on
page 187.
Step 3. Shut down the SNC 5100.
Step 4. Remove the cable from one attached SCSI device, and attach it as a
loop back cable to the SNC 5100.
Step 5. Power on the SNC 5100.
Step 6. After the SNC 5100 has finished booting, enter the
scsiChannelTest(x,y) command from the service terminal
(where ‘
x’ and ‘y’ are the slot numbers connected by the loopback
cable) to perform a loop back test.
For an example, see “SCSI Loop Back Test” on page 58, Step 8.
Step 7. If the SNC 5100 returns a FAILED status, the cable is faulty and
must be replaced.
If the SNC 5100 returns a PASSED status, go to "Isolating SCSI
devices" to isolate bad devices on the SCSI bus.
Isolating SCSI devices
Step 1. Restore the SNC 5100 to normal operation.
See “Restoring Normal Mode” on page 188.
Step 2. Power down the SNC 5100.
Step 3. Perform Steps 4 - 11 for each SCSI device that was found missing
in Step 1 under “Compare Listed versus Physical Devices” on
page 52.