Apple xserve g5 or xserve g5 january 2005 User Manual

							
Xserve G5 Take Apart - 69
 Logic Board
Part Location
Note:  The version 2 logic board is shown above. 
						

							
70 - Xserve G5 Take Apart
 Logic Board
Procedure
1. Disconnect the FireWire cable from the logic board
2. Release the two locking levers on the front panel board cable connector and 
disconnect the cable from the logic board.
3. Disconnect the three-headed drive cable from the logic board.
4. Release the locking tab and disconnect the power cable from the logic board.
5. Fold the cables out of the way toward the front of the server. 
						

							
Xserve G5 Take Apart - 71
 Logic Board 6. Using a Phillips screwdriver, release the thumbscrew that secures the logic board to 
the chassis (indicated by a triangle in the illustration below).
Note:  The thumbscrew is captive; you cannot remove it.
7. Grasping the logic board by its long edges, move it forward and up slightly to release it  from the four mounting pegs (indicated by squares in the illustration below).
Caution : Be careful not to  flex the logic board, which could damage the board or its 
components. To minimize  flexing, always grasp the logic board by its long edges when 
removing or installing it.
8. Grasping the long edges of the logic board, tilt up the front end of the l\
ogic board so  that the board ports clear the openings in the back of the enclosure.
9. Grasp the logic board by its long edges and remove it from the server.  Make sure the  board clears the two chassis release levers. 
						

							
72 - Xserve G5 Take Apart
 Logic Board
Important:
 When replacing the logic board, make sure the board’s connectors  fit through 
the appropriate openings in the server’s back panel. Take special care to  fit the clear 
plastic system identi fier button through its opening. (The system identi fier button is located 
low on the back panel, to the left of center.) 
Caution : Be careful not to  flex the logic board, which could damage the board or its 
components. To minimize  flexing, always grasp the logic board by its long edges when 
removing or installing it.
After installing a replacement logic board, be sure to transfer any PCI cards, risers, and 
DIMMs to the new board. You must also remove the battery insulator tab from the battery 
holder on the new board. 
Note:  Replacing the logic board in the server changes its Ethernet ID number. The new 
number is printed on an Ethernet label packaged with the replacement logic board. After 
installing the new logic board, place the new Ethernet label over the original Ethernet 
number on the server’s back pane 
						

							
 

© 2005 Apple Computer, Inc. All rights reserved.
 

 
 
 
Service Source
Troubleshooting
 
Xserve G5 
						

							
 

Xserve G5 Troubleshooting - 
 
1
 
 General Information
 
General Information
 
What’s New
 
Hot-Pluggable Serial ATA Drives
 
Xserve G5 and Xserve G5 (January 2005) include three hard drive bays at the front of the 
server; Xserve G5 (Cluster Node) includes just one hard drive. All versions support hot-
pluggable Apple serial ATA (SATA) drive modules. 
In the Xserve G5/Xserve G5 (January 2005) server, drive bays are numbered 1–3, 
beginning with the far left bay. The bay in which a drive is installed determines its master/
slave position, thereby eliminating the need for jumpers or special drive configuration. The 
drive installed in bay 1 is the master drive and should have the operating system installed 
on it.
 In both models, you can replace or install hard drives while the server is running; you do 
not need to shut down or open the server  first. A status light on the front of each drive 
indicates when it is safe to remove the drive without losing data. For more information, see 
“Hard Drive” in the Take Apart chapter.
 
DDR Memory
 
The server’s logic board includes eight memory slots, arranged in two banks. The slots 
accept error-correcting Double-Data-Rate (DDR) Synchronous Dynamic Random-Access 
Memory (SDRAM) devices. Memory can be expanded to a maximum of 16 gigabytes 
using the 2 GB DIMMs introduced in March 2005. 
DIMMs used in Xserve G5 must  fit these speci fications:
• PC3200 error-correcting DDR SDRAM, also known as DDR-400
• 2.5 volt
• 64-bit wide, 184-pin module
• 18 memory devices maximum
• Unbuffered (not registered or buffered)
• Maximum height of 1.25 inches
For more information, see “DIMMs” in the Take Apart chapter.
 
Important:
 
 DIMMs must always be installed in pairs of equal size, from the center 
outward. Memory from older Macintosh computers is not compatible with Xserve G5. Do 
not use older memory, even if it  fits into the DIMM slots. 
						

							
 

2 - 
 
Xserve G5 Troubleshooting General Information
 
Ports
 
The standard configuration of Xserve G5 includes the following ports on the back panel: 
two gigabit Ethernet ports, two FireWire 800 ports, two USB 2.0 ports, and a serial port 
that supports RS-232 or RS-422 connection. There is also one FireWire 400 port on the 
front of the server.
System administrators or service providers can connect a laptop computer or terminal to 
the serial port and then use command-line tools to change settings on the server. The 
connection requires a serial cable with these speci fications:
• DB9 connector
• 8-bit
• no parity
• 1 stop bit
• 9600 kbps
 
Note:
 
 For a diagram of the ports location, see “External Views” in the \
Views chapter.
 
PCI and PCI-X Cards
 
All versions of Xserve G5 include two slots available for PCI or PCI-X expansion cards. 
The slots are on a riser card located at the back corner of the logic board. 
The server accommodates PCI or PCI-X cards that meet the following requirements:
• 32 or 64-bit data width
• 33, 66, 100, or 133 MHz frequency (133 MHz is available only when a sin\
gle card is  installed; if two cards are installed, both cards operate at the speed o\
f the slower 
card.)
• 3.3 volt signaling (PCI-X cards must have a 3.3 volt connector or a uni\
versal connector  to fit into the expansion slots; cards with a 5 volt connector will not \
work in this server.)
• 7 to 12 inches long
 
Note:
 
 Combined power consumption for all expansion slots within one unit should not 
exceed 30 W.
 
Version 2 Main Logic Board and 2 GB Memory DIMMs
 
2 gigabyte memory modules became a con figurable purchase option for Xserve G5 
computers starting in March 2005. Only Xserve G5 version 2 logic boards labeled “DDR 
2GB” accept 2 gigabyte (GB) memory modules (DIMMs). Make sure 2 GB DIMMs are 
installed on version 2 logic boards only. Refer to the Take Apart/Logic Board procedure for 
more information. 
						

							
 

Xserve G5 Troubleshooting - 
 
3
 
 General Information
 
Resetting the PMU on the Logic Board
 
The PMU (Power Management Unit) is a microcontroller chip that controls all power 
functions for the server. The PMU is a computer within a computer. Its function is to: 
• tell the server to turn on, turn off, sleep, wake, idle, etc.
• manage system resets from various commands.
• maintain parameter RAM (PRAM).
• manage the real-time clock.
 
Important:
 
 Be very careful when handling the logic board. The PMU is very sensitive and 
touching the circuitry on the logic board can cause the PMU to crash. If the PMU crashes 
and is not reset, the battery life goes from about  five years to about two days.
 
Note:
 
 For the location of the PMU reset button, see “Logic Board” in th\
e Views chapter.
Many system problems can be resolved by resetting the PMU chip. When you have a 
server that fails to power up, follow this procedure before replacing any modules: 
1. Disconnect the power cord and check the battery in the battery holder. The battery  should read 3.3 to 3.7 volts. If the battery is bad, replace it, wait ten seconds, and then 
proceed to step 2. If the battery is good, go directly to step 2.
2. Press the PMU reset button once and then proceed to step 3. Do not press the PMU  reset button a second time because it could crash the PMU chip.
3. Wait ten seconds before connecting the power cord and powering on the server. If the  server powers on, go to step 4. If the server does not power on, there is something 
else wrong with it; refer to the “Startup” section of “Symptom Charts” in this chapter.
4. Run Xserve Remote Diagnostics to verify the system.
 
Note:
 
  The above procedure resets the server’s PRAM. After resetting the PMU, be sure to 
reset the time, date, and other system parameter settings. 
						

							
 

4 - 
 
Xserve G5 Troubleshooting General Information
 
Power Supply Verification
 
If the server fails to power on,  first reset the PMU. Then follow the procedure outlined 
below to determine whether the problem is related to the power supply.
 
Note:
 
 To verify the power supply, you need a volt meter. When connecting the volt meter 
leads to speci fic pins, make sure the power supply remains securely plugged into its 
connector on the logic board.
The following  figure shows the pins and voltage on the server’s power supply connector, 
as viewed from above when it is connected to the logic board.
 
 
 
1. Plug a known-good power cord into the server. Do not turn on the server.
2. Connect the black lead of the volt meter to pin 8 of the power supply connector;  connect the red lead of the volt meter to pin 1. The volt meter should measure 
approximately +12V.
If you do not get a reading of +12V, recheck the volt meter connections \
and measure 
the voltage again. If voltage is still not present, replace the power su\
pply.
If you do measure +12V on pin 1, the power supply is likely OK. 
 
RAM and Processor Veri fication: Power-On Self Test
 
A power-on self test in the server’s ROM automatically runs whenever the server is started 
up after being fully shut down (the test does not run if the server is only restarted). If the 
test detects a problem, you will not see a normal sequence of system activity lights on the 
front panel during startup. Instead, the Power light will  flash in the following ways:
•
 
1 Flash: 
 
No RAM is installed or detected.
•
 
2 Flashes: 
 
 Incompatible RAM types are installed.
•
 
3 Flashes: 
 
No RAM banks passed memory testing.
•
 
4 Flashes: 
 
No good boot images are detected in the boot ROM (and/or there is a bad\
 
sys config block).
Pin 1  +12VDC
Pin 2  +12VDC
Pin 3 +12VDC
Pin 4 IICclk
Pin 5 +12VDC
Pin 6 +12VDC
Pin 7 +12VDC 
 GND Pin 8
GND Pin 9
IICdat Pin 10 IICrtn Pin 11
GND  Pin 12
GND  Pin 13
GND  Pin 14 
						

							
 

Xserve G5 Troubleshooting - 
 
5
 
 General Information
 
Entering Firmware Boot Commands From the Front Panel
 
You can use the system identifier button on the Xserve G5  server’s front panel to initiate a 
limited number of  firmware commands to the system without connecting a keyboard or 
monitor to the server. The commands are listed below; you enter each command with a 
combination of the system ID button and a speci fic light on the front panel.
 
Note:
 
 If Open Firmware Security is turned on for the system, front panel mode is not 
available. In this situation, the two rows of lights on the front panel  flash twice when you try 
to enter a boot command with the system identi fier. Then the system resumes its regular 
startup sequence.
Follow these steps to initiate a command from the front panel.
1. With the power off, hold in the system ID button while you press the on button.
2. Continue holding in the system ID button until the top row of blue lights blinks  sequentially.
3. Release the system ID button. The rightmost light in the bottom row turns on. Press  the button to light the next light in the bottom row, moving from right to left. Press the 
button again to change lights.
The lights in the bottom row indicate (from right to left):
• Light 1 (far right): Start up from the system disc (also ejects any d\
isc in the optical  drive)
• Light 2: Start up from a network server (NetBoot)
• Light 3: Start up from the internal drive (leftmost drive if more than \
one)
• Light 4: Bypass the current startup disk and start up from any other ava\
ilable startup  disk
• Light 5: Begin target disk mode (all drives, including the optical driv\
e, will show up)
• Light 6: Restore the system’s default settings (reset NVRAM)
• Light 7: Enter Open Firmware (via the serial port if no monitor/keyboar\
d connected)
• Light 8: Enter diagnostic test mode
4. When the light for the action you want is on, hold in the system identi fier button for at 
least 2 seconds, until all lights in the top row are on.
5. Release the button.
 
Diagnostic Tools
 
Xserve G5 includes built-in sensors that report on hard drives, internal temperature, fan 
status/failure, and power status/failure. These sensors allow you to monitor the server’s 
operation via indicator lights on the front of the server and remote monitoring software.