Supermicro 4020A-8R, User Manual

Page: 53 / 104

Chapter 5: Advanced Serverboard Setup
5-19
5-10 Jumper Settings
Explanation of
Jumpers
To m o di f y t h e o p e r at i o n of t h e
serverboard, jumpers can be used
to choose between optional settings.
Jumpers create shorts between two
pins to change the function of the
connector. Pin 1 is identifi ed with a
square solder pad on the printed circuit
board. See the diagram at right for
an example of jumping pins 1 and 2.
Refer to the serverboard layout page
for jumper locations.
Note 1: On two-pin jumpers, "Closed"
means the jumper is on and "Open"
means the jumper is off the pins.
CMOS Clear
JBT1 is used to clear CMOS and will also clear any passwords. Instead of pins,
this jumper consists of contact pads to prevent accidentally clearing the contents
of CMOS.
To clear CMOS,
1) First power down the system and unplug the power cord(s).
2) With the power disconnected, short the CMOS pads with a metal object such as
a small screwdriver for at least four seconds.
3) Remove the screwdriver (or shorting device).
4) Reconnect the power cord(s) and power on the system.
Notes:
Do not use the PW_ON connector to clear CMOS.
The onboard battery does not need to be removed when clearing CMOS, however
you must short JBT1 for at least four seconds.
Connector
Pins
Jumper
Setting
3 2 1
3 2 1
JBT1 contact pads