About CautionsCAUTION: A CAUTION indicates a potential for property damage, personal injury, or death.Information UpdateThis document provides updated information about your system.CAUTION: Only trained service technicians are authorized to remove the system cover and access any ofthe components inside the system. See your Product Information Guide for complete information about safetyprecautions, working inside the computer, and protecting against electrostatic discharge.Update to Processor InstallationWhen removing or installing the processor, be sure to position your finger or thumb firmly on the socketrelease lever and control the lever when releasing it so that the lever does not spring up suddenly. Thelever locks down the processor with considerable force to ensure a good socket connection. Releasingthe lever without control can cause the lever to spring up suddenly and forcefully.Replacing a Power Distribution Board or System Board(Service-Only Procedure)When replacing the power distribution board or the system board, be careful when connecting the powerdistribution cable between the two boards that you do not bend or damage the pins on the system boardconnector. Bent signal pins can prevent the system from recognizing the presence of the power supplies.To avoid damage, align the black cable connector on the gray power-control ribbon cable with the pins onthe black connector on the system board and press the connector straight down evenly until it is seated.Figure 1 shows the location of the power distribution control cable connector on the system board.For information on replacing the power distribution board or system board, see "Installing SystemComponents" in your system Hardware Owner’s Manual.October 2006FP394ap1.fm Page 9 Tuesday, November 14, 2006 4:21 PM