Sun Microsystems 220R service manual What to Do, Set the main logic board jumpers J2703 and J2804

3.16.2What to Do

1.Locate the jumpers on the main logic board.

A main logic board jumper is identified by its jumper address, labeled on the board with the letter “J” followed by four numbers (JXXXX). Jumper pins are located immediately adjacent to the jumper address. On the board, pin 1 is marked with an asterisk.

For information about jumper locations, see Section 3.15 “How to Set the Serial Port Jumpers” on page 122.

2.Set the main logic board jumpers J2703 and J2804.

Using long-nose pliers, place a shunt over the appropriate pins according to the following table.

Flash PROM	A shunt on	A shunt on	The default	Signal that is
jumper	pins 1 and 2	pins 2 and 3	shunt is on	controlled
	selects	selects	pins
J2703	Write-protect	Write-enable	1 and 2	FLASH PROM
				PROG
				ENABLE
J2804	High-half	Normal	2 and 3	XOR LOGIC
	booting	(low-half)		SET
		booting

3.16.3What Next

4Complete the following task to reassemble the system:

Section 2.7 “How to Replace the System Cover” on page 67

Servicing the Main Logic Board and Components 125