Service manual

Appendix C Functional Description C-31
1. Power off the system unit.
See Section 6.2 “Powering Off the System Unit” on page 6-2.
2. Remove the system unit cover.
See Section 7.1 “Removing the System Unit Cover” on page 7-1.
Caution – Use proper 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 it on any surface.
3. Attach the wrist strap.
See Section 7.2 “Attaching the Wrist Strap” on page 7-3.
4. Locate the jumpers on the motherboard and change the selection of jumpers
J2104 and J2105 to position B.
5. Detach the wrist strap.
6. Replace the system unit cover.
See Section 7.3 “Replacing the System Unit Cover” on page 7-4.
7. Power on the system unit.
See Section 6.1 “Powering On the System Unit” on page 6-1.
C.5.2 Flash PROM Jumpers
Flash PROM jumpers J2202, J2203, and J2204 permit the reprogramming of specific
code blocks. The following table identifies the flash PROM jumper settings. The
default setting of J2202 through J2204 is located on pins 1 and 2. The following table
identifies the signals controlled by the non-default settings of jumpers J2203 and
J2004.
TABLE C-7 Serial Port Jumper Settings
Jumper Pins 1 + 2 Select Pins 2 + 3 Select Default Jumper on Pins Signal Controlled
J2104 RS-232 RS-423 2 + 3 RS-232/RS-423 SEL
J2105 RS-232 RS-423 2 + 3 RS-232/RS-423 SEL