Quick Reference
9-10 AlphaServer 1000A Rackmount Owner’s Guide
LEDs
Table 9–6 describes system LEDs and their function.
Table 9–6: LEDs
LED
Function
On/Off indicator (green)
Lights when the system unit is turned on.
Diskette drive activity indicator (green)
Lights when the system is accessing the diskette
drive.
CD-ROM drive activity indicator
(green)
Lights when the system is accessing the CD-ROM
drive.
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
J16
Large fan
Allows the large fan to be disabled. Enabled.
J27
VGA enable
Enables the on-board VGA logic. Enabled.
Set to disabled position (pins 2 and 3) when
using a graphics option card
J50
FROM VPP enable
Permits the 12 volts needed to update the Flash
ROMs. Enabled.
J51
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.
J53
Fan shut down
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.
