Sun Microsystems 220R manual About the Main Logic Board Jumpers

About the Main Logic Board Jumpers

The jumpers on the main logic board have the following functions:

■To configure the serial ports for either EIA-423 or EIA-232D operation. For information about the EIA-423/232D jumper settings, and about configuring them, see “About Serial Port Jumpers” on page 82.

■To affect the operation of the flash PROM located on the main logic board. For information about the flash PROM jumper settings, see “About Flash PROM Jumpers” on page 83.

Modifying jumper settings can only be performed by a qualified service provider. For more information about changing jumper settings, see the Sun Enterprise 220R Server Service Manual.

Jumpers are marked on the main logic board with jumper addresses. For example, the serial port jumpers are marked J2604 and J2605. Jumper pins are located immediately adjacent to the jumper address. Pin 1 is marked with an asterisk (*) in one of the positions shown below.

J X X X X

*

*

*

	Jumper address
	Pins
*			Asterisk indicates pin 1
		*
*

Chapter 4 Hardware Configuration 81