IBM 3590 - Manual (Page 27)

From left to right in Figure 2, the push buttons and the indicator are as
follows:
Reset
1
A push button that allows the service representative to perform a
device power-on reset.
Note: It is recommended that all SCSI ports be taken offline before
resetting the drive. See “Services Menu” on page 33.
Change Mode
2
A push button that allows the service representative to toggle between
service representative mode and Normal mode. Service representative
mode can be selected at any time, but the mode will not become
active until the device completes all current operations. Normal mode
can be selected at any time. Selecting Normal mode returns the
operator panel menu to the Operator menu (that indicates status and
conditions). Service representative mode enables special menus on the
operator panel display not available to the operator in Normal mode.
Up Arrow
3
A push button that allows the operator or the service representative to
move the cursor arrow up through the menu options.
Down Arrow
4
A push button that allows the operator or the service representative to
move the cursor arrow down through the menu options.
Figure 2. Operator Panel
Chapter 3. Drive Operator Panel and Controls 7