Quick Reference
AlphaServer 1000 Rackmount Owner's Guide 9-11
System Board Jumper Settings
Table 9–7 lists the default jumper settings for the system board.
Table 9–7: System Board Default Jumper Settings
Number
Name
Description and Default
J49
SCSI terminator
Enables the on-board SCSI terminators. The
system specification requires that the SCSI bus
be terminated at both ends. Enabled.
J52
Temperature shutdown
Allows the temperature chips to shut down the
system in an orderly sequence. Enabled.
J50
FROM VPP enable
Connects 12 volts from the power supply to the
VPP pins of the Flash ROMs. Enabled.
J27
VGA enable
Enables the on-board VGA logic. Enabled. Set
to the disabled position (pins 2 and 3) when
using a graphics option card.
J53
Fan shut
Allows the software to shut down the system in
an orderly sequence. Enabled.
J55
Fan-2 Fault
Allows hardware to detect Fan-2 fault and to
shutdown the system in an orderly sequence.
Disabled.
J56
Fan fault
Allows hardware to detect a fan fault and shut
down the system in an orderly sequence.
Enabled.
Set to disable if testing the system board or
CPU card outside the enclosure.