C-46 Sun Ultra 60 Service Manual • August 2001
C.4.1 Serial Port Jumpers
Serial port jumpers J2604 and J2605 can be set to either RS-423 or RS-232 serial
interface. The jumpers are preset for RS-423. RS-232 is requiredfor digital
telecommunicationwithin the European Community.TABLE C-16 identifies serial port
jumper settings. If the system is being connected to a public X.25 network, the serial
port mode jumper setting may need to change from RS-423 to RS-232 mode.
Tochange the serial port mode jumper setting:
1. Power off the system unit.
See Section6.2, “Powering Off the System Unit” on page 6-3.
2. Remove the side access cover.
See Section7.1, “Removing the Side Access Cover” on page 7-2.
Caution – Useproper ESD grounding techniques when handling components. Wear
an antistatic wriststrap and use an ESD-protected mat. Store ESD-sensitive
components in antistatic bags before placing them on any surface.
3. Attach the wrist strap.
See Section7.2, “Attaching the Wrist Strap” on page 7-3.
4. Locate the jumpers on the system board. Change the J2604 and J2605 jumper
selection.
See TABLEC-16.
5. Detach the wrist strap.
6. Replace the side access cover.
See Section7.3, “Replacing the Side Access Cover” on page 7-4.
7. Power on the system unit.
See Section6.1, “Powering On the System Unit” on page 6-2.
TABLEC-16 Serial Port Jumper Settings
Jumper Pins1 + 2 Select Pins2 + 3 Select DefaultJumper
onPins
J2604 RS-232 RS-423 2+ 3
J2605 RS-232 RS-423 2+ 3