Asus M2N68 AM - Motherboard - Micro ATX User manual

Motherboard
M2N68-AM

ii
Copyright © 2008 ASUSTeK Computer Inc. All Rights Reserved.
No part of this manual, including the products and software described in it, may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language in any form or by any
means, except documentation kept by the purchaser for backup purposes, without the express written
permission of ASUSTeK Computer Inc. (“ASUS”).
Product warranty or service will not be extended if: (1) the product is repaired, modied or altered, unless
such repair, modication of alteration is authorized in writing by ASUS; or (2) the serial number of the
product is defaced or missing.
ASUS PROVIDES THIS MANUAL “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR CONDITIONS OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL ASUS, ITS
DIRECTORS, OFFICERS, EMPLOYEES OR AGENTS BE LIABLE FOR ANY INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF PROFITS,
LOSS OF BUSINESS, LOSS OF USE OR DATA, INTERRUPTION OF BUSINESS AND THE LIKE),
EVEN IF ASUS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES ARISING FROM ANY
DEFECT OR ERROR IN THIS MANUAL OR PRODUCT.
SPECIFICATIONS AND INFORMATION CONTAINED IN THIS MANUAL ARE FURNISHED FOR
INFORMATIONAL USE ONLY, AND ARE SUBJECT TO CHANGE AT ANY TIME WITHOUT NOTICE,
AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY ASUS. ASUS ASSUMES NO
RESPONSIBILITY OR LIABILITY FOR ANY ERRORS OR INACCURACIES THAT MAY APPEAR IN THIS
MANUAL, INCLUDING THE PRODUCTS AND SOFTWARE DESCRIBED IN IT.
Products and corporate names appearing in this manual may or may not be registered trademarks or
copyrights of their respective companies, and are used only for identication or explanation and to the
owners’ benet, without intent to infringe.
E4417
Fourth Edition V4
December 2008

iii
Contents
Notices......................................................................................................... vi
Safety information ..................................................................................... vii
About this guide ........................................................................................ vii
M2N68-AM specications summary ......................................................... ix
Chapter 1: Product introduction
1.1 Welcome! ...................................................................................... 1-1
1.2 Package contents......................................................................... 1-1
1.3 Special features............................................................................ 1-1
1.3.1 Product highlights ........................................................... 1-1
1.3.2 Innovative ASUS features ............................................... 1-3
1.4 Before you proceed ..................................................................... 1-4
1.5 Motherboard overview................................................................. 1-5
1.5.1 Placement direction ........................................................ 1-5
1.5.2 Screw holes .................................................................... 1-5
1.5.3 Motherboard layout ......................................................... 1-6
1.5.4 Layout contents............................................................... 1-6
1.6 Central Processing Unit (CPU) ................................................... 1-7
1.6.1 Installing the CPU ........................................................... 1-7
1.6.2 Installing the heatsink and fan ........................................ 1-9
1.7 System memory ......................................................................... 1-10
1.7.1 Overview ....................................................................... 1-10
1.7.2 Memory congurations...................................................1-11
1.7.3 Installing a DIMM .......................................................... 1-16
1.7.4 Removing a DIMM ........................................................ 1-16
1.8 Expansion slots.......................................................................... 1-17
1.8.1 Installing an expansion card ......................................... 1-17
1.8.2 Conguring an expansion card ..................................... 1-17
1.8.3 PCI slots........................................................................ 1-17
1.8.4 PCI Express x1 slot....................................................... 1-17
1.8.5 PCI Express x16 slot..................................................... 1-17
1.9 Jumpers ...................................................................................... 1-18
1.10 Connectors ................................................................................. 1-19
1.10.1 Rear panel ports ........................................................... 1-19
1.10.2 Internal connectors ....................................................... 1-20

iv
Contents
1.11 Software support........................................................................ 1-28
1.11.1 Installing an operating system ...................................... 1-28
1.11.2 Support DVD information .............................................. 1-28
Chapter 2: BIOS information
2.1 Managing and updating your BIOS ............................................ 2-1
2.1.1 Creating a bootable oppy disk....................................... 2-1
2.1.2 ASUS Update utility ........................................................ 2-2
2.1.3 ASUS EZ Flash 2 utility................................................... 2-3
2.1.4 AFUDOS utility................................................................ 2-4
2.1.5 ASUS CrashFree BIOS 3 utility ...................................... 2-5
2.2 BIOS setup program .................................................................... 2-6
2.2.1 BIOS menu screen.......................................................... 2-7
2.2.2 Menu bar......................................................................... 2-7
2.2.3 Navigation keys............................................................... 2-8
2.2.4 Menu items ..................................................................... 2-8
2.2.5 Submenu items ............................................................... 2-8
2.2.6 Conguration elds ......................................................... 2-8
2.2.7 Pop-up window ............................................................... 2-8
2.2.8 Scroll bar......................................................................... 2-8
2.2.9 General help ................................................................... 2-8
2.3 Main menu .................................................................................... 2-9
2.3.1 System Time ................................................................... 2-9
2.3.2 System Date ................................................................... 2-9
2.3.3 Legacy Diskette A ........................................................... 2-9
2.3.4 IDE Conguration............................................................ 2-9
2.3.5 Primary IDE Master/Slave............................................. 2-10
2.3.6 SATA1~4 ........................................................................2-11
2.3.7 System Information ....................................................... 2-12
2.4 Advanced menu ......................................................................... 2-12
2.4.1 JumperFree Conguration ............................................ 2-12
2.4.2 CPU Conguration ........................................................ 2-14
2.4.3 Chipset.......................................................................... 2-14
2.4.4 Onboard Devices Conguration.................................... 2-16
2.4.5 PCI PnP ........................................................................ 2-17
2.4.6 USB Conguration ........................................................ 2-17

v
Contents
2.5 Power menu................................................................................ 2-18
2.5.1 Suspend Mode.............................................................. 2-18
2.5.2 ACPI
Version Features................................................. 2-18
2.5.3 ACPI APIC Support....................................................... 2-18
2.5.4 APM Conguration........................................................ 2-19
2.5.5 Hardware Monitor ......................................................... 2-19
2.6 Boot menu .................................................................................. 2-20
2.6.1 Boot Device Priority ...................................................... 2-20
2.6.2 Boot Settings Conguration .......................................... 2-20
2.6.3 Security ......................................................................... 2-21
2.7 Tools menu ................................................................................. 2-23
2.7.1 ASUS EZ Flash 2.......................................................... 2-23
2.7.2 AI NET 2........................................................................ 2-23
2.8 Exit menu.................................................................................... 2-24

vi
Notices
Federal Communications Commission Statement
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions:
• This device may not cause harmful interference, and
• This device must accept any interference received including interference that may cause
undesired operation.
This equipment has been tested and found to comply with the limits for a Class B digital
device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This
equipment generates, uses and can radiate radio frequency energy and, if not installed
and used in accordance with manufacturer’s instructions, may cause harmful interference
to radio communications. However, there is no guarantee that interference will not occur
in a particular installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment to an outlet on a circuit different from that to which the receiver is
connected.
• Consult the dealer or an experienced radio/TV technician for help.
The use of shielded cables for connection of the monitor to the graphics card is required
to assure compliance with FCC regulations. Changes or modications to this unit not
expressly approved by the party responsible for compliance could void the user’s authority
to operate this equipment.
Canadian Department of Communications Statement
This digital apparatus does not exceed the Class B limits for radio noise emissions from
digital apparatus set out in the Radio Interference Regulations of the Canadian Department
of Communications.
This class B digital apparatus complies with Canadian ICES-003.
DO NOT throw the motherboard in municipal waste. This product has been designed to
enable proper reuse of parts and recycling. This symbol of the crossed out wheeled bin
indicates that the product (electrical and electronic equipment) should not be placed in
municipal waste. Check local regulations for disposal of electronic products.
DO NOT throw the mercury-containing button cell battery in municipal waste. This symbol
of the crossed out wheeled bin indicates that the battery should not be placed in municipal
waste.

vii
Safety information
Electrical safety
• To prevent electric shock hazard, disconnect the power cable from the electric outlet
before relocating the system.
• When adding or removing devices to or from the system, ensure that the power cables
for the devices are unplugged before the signal cables are connected. If possible,
disconnect all power cables from the existing system before you add a device.
• Before connecting or removing signal cables from the motherboard, ensure that all
power cables are unplugged.
• Seek professional assistance before using an adapter or extension cord. These devices
could interrupt the grounding circuit.
• Ensure that your power supply is set to the correct voltage in your area. If you are not
sure about the voltage of the electrical outlet you are using, contact your local power
company.
• If the power supply is broken, do not try to x it by yourself. Contact a qualied service
technician or your retailer.
Operation safety
• Before installing the motherboard and adding devices on it, carefully read all the manuals
that came with the package.
• Before using the product, ensure that all cables are correctly connected and the power
cables are not damaged. If you detect any damage, contact your dealer immediately.
• To avoid short circuits, keep paper clips, screws, and staples away from connectors,
slots, sockets and circuitry.
• Avoid dust, humidity, and temperature extremes. Do not place the product in any area
where it may become wet.
• Place the product on a stable surface.
• If you encounter technical problems with the product, contact a qualied service
technician or your retailer.
About this guide
This user guide contains the information you need when installing and conguring the
motherboard.
How this guide is organized
This guide contains the following parts:
• Chapter 1: Product introduction
This chapter describes the features of the motherboard and the new technology it
supports.
• Chapter 2: BIOS information
This chapter tells how to change system settings through the BIOS Setup menus.
Detailed descriptions of the BIOS parameters are also provided.

viii
Conventions used in this guide
To ensure that you perform certain tasks properly, take note of the following symbols used
throughout this manual.
DANGER/WARNING:Information to prevent injury to yourself when trying to
complete a task.
CAUTION: Information to prevent damage to the components when trying to
complete a task.
NOTE: Tips and additional information to help you complete a task.
IMPORTANT: Instructions that you MUST follow to complete a task.
Where to nd more information
Refer to the following sources for additional information and for product and software
updates.
1. ASUS websites
The ASUS website provides updated information on ASUS hardware and software
products. Refer to the ASUS contact information.
2. Optional documentation
Your product package may include optional documentation, such as warranty yers,
that may have been added by your dealer. These documents are not part of the
standard package.
Typography
Bold text Indicates a menu or an item to select.
Italics Used to emphasize a word or a phrase.
<Key> Keys enclosed in the less-than and greater-than sign means
that you must press the enclosed key.
Example: <Enter> means that you must press the Enter or
Return key.
<Key1>+<Key2>+<Key3> If you must press two or more keys simultaneously, the key
names are linked with a plus sign (+).
Example: <Ctrl>+<Alt>+<D>
Command Means that you must type the command exactly as shown,
then supply the required item or value enclosed in
brackets.
Example: At the DOS prompt, type the command line:
afudos /i[lename]
afudos /iM2N68AM.ROM

ix
M2N68-AM specications summary
(continued on the next page)
CPU AMD socket AM2/AM2+ for AMD Phenom™ FX /
Phenom™ / Athlon™ / Sempron™ processors
AMD64 architecture enables simultaneous 32-bit and
64-bit computing
Supports AMD Cool ‘n’ Quiet™ Technology
Chipset MCP68S/MCP68PVNT
System bus 2000 / 1600 MT/s
Memory Dual-channel memory architecture 2 x 240-pin DIMM
sockets support up to 4GB of unbufferred ECC and
non-ECC 1066 / 800 / 667 / 533 MHz DDR2 memory
modules
Notes*:
• Only AM2+ supports DDR2 1066.
• When you install total memory of 4GB or more,
Windows® 32-bit operating system may only recognize
less than 3GB. Hence, a total installed memory of less
than 3GB is recommended if you are using a 32-bit
Windows operating system.
Expansion slots 1 x PCI Express™ x16 slot
1 x PCI Express™ x1 slot
2 x PCI slots
Graphics Integrated Nvidia®GeForce® 7 Series Shader model 3.0
DirectX9 graphics processor
Maximum shared memory of 256 MB
Supports RGB with max. resolution 1920 x 1440
(@70MHz*32bpp / 75Mhz*16bpp)
Notes*:
• Due to the chipset limitation, only MPEG 2 & WMV
Ofoad can support HD format 1920 x 1080p
• The suggested system conguration when playing HD
DVD and Blu-ray disc: DDR2 800 1GB x 2 / Althon
64 x 2 4400+ / Graphic shared memory 256 MB /
Purevideo HD support.
Storage - 1 x Ultra DMA 133 / 100 interface
- 4 x Serial ATA 3 Gb/s hard disk drives supporting
RAID 0, RAID 1, RAID 5, RAID 10, and JBOD
congurations
- ATAPI support, AHCI mode
Supported OS Windows Vista/XP
High denition audio ALC662 High Denition Audio 6-channel CODEC
Supports Anti Pop Function
Supports S/PDIF Out interface, Jack-detect, and
multi-streaming
USB Supports up to 10 USB 2.0 / 1.1 ports (6 on the board, 4
at the rear panel)

x
M2N68-AM specications summary
*Specications are subject to change without notice.
LAN RTL8211CL PHY Gigabit LAN
BIOS features 8 Mb Flash ROM, AMI BIOS, PnP, DMI2.0, WfM2.0,
SM BIOS 2.5
Manageability WfM2.0, DMI2.0, WOR by Ring, PME Wake Up, PXE
WO_USB, WO_KB/MS
ASUS Special Features ASUS Q-Fan
ASUS CrashFree BIOS 3
ASUS EZ Flash 2
ASUS MyLogo 2
Rear panel ports 1 x LAN (RJ-45) port
1 x COM port
1 x LPT
1 x VGA port
1 x PS/2 keyboard port
1 x PS/2 mouse port
6-channel audio ports
4 x USB 2.0 ports
Internal connectors 1 x High Denition front panel audio connector
1 x IDE connector
1 x Floppy disk drive connector
1 x CD audio-in connector
1 x CPU fan connector
1 x S/PDIF Out connector
3 x USB 2.0 connectors for 6 additional USB 2.0 ports
1 x 24-pin EATX power connector
1 x 4-pin ATX 12V power connector
1 x System panel connector
Support DVD contents Device drivers
ASUS PC Probe II
ASUS Live Update utility
Anti-virus software (OEM version)
Accessories 1 x Serial ATA cable
1 x Serial ATA power cable
1 x Ultra DMA 133 / 100 / 66 cable
1 x I/O Shield
User Manual
Form factor MicroATX: 9.6 in. x 8.75 in. (24.4 cm x 22.2 cm)

1.2 Package contents
Check your motherboard package for the following items.
Motherboard ASUS M2N68-AM motherboard
Cables 1 x Serial ATA cable
1 x Serial ATA power cable
1 x Ultra DMA 133/100/66 cable
Accessories 1 x I/O shield
Application DVD ASUS motherboard support DVD
Documentation User Manual
If any of the above items is damaged or missing, contact your retailer.
Chapter 1
Product introduction
1.3 Special features
1.3.1 Product highlights
1.1 Welcome!
Thank you for buying an ASUS® M2N68-AM motherboard!
The motherboard delivers a host of new features and latest technologies, making it another
standout in the long line of ASUS quality motherboards!
Before you start installing the motherboard, and hardware devices on it, check the items in
your package with the list below.
Latest processor technology
This motherboard supports AMD socket AM2/AM2+ for AMD
Phenom™ FX / Phenom™ / Athlon™ / Sempron™ processors with
2MB / 1MB / 512KB L2 cache, which is based on 64-bit architecture.
It features 2000 / 1600 MT/s HyperTransport Bus, dual-channel
un-buffered DDR2 1066 memory support and AMD Cool ‘n’ Quiet
Technology.
AMD Cool ‘n’ Quiet Technology
This motherboard supports the AMD Cool ‘n’ Quiet Technology, which
monitors system operation and automatically adjusts CPU voltage
and frequency for a cool and quiet operating environment.
Chapter 1: Product introduction 1-1

DDR2 1066 is for AM2+ only.
64-bit CPU support
64-bit computing, the technology to replace 32-bit architecture,
delivers advanced system performance, faster memory access
and increased productivity. This motherboard provides excellent
compatibility and exibility by supporting either 64-bit or 32-bit
architecture.
NVIDIA®GeForce™ 7025 / nForce™ 630a
The NVIDIA® GeForce™ 7025 integrates NVIDIA® GeForce™
7 Series Shader model 3.0 DirectX 9.0 graphics processor. The
NVIDIA® nForce™ 630a MCP delivers NVIDIA®Gigabit LAN, and
NVIDIA®MediaShield storage management technology allowing easy
RAID conguration (RAID 0, RAID 1 ,RAID 10 ,RAID 5, and JBOD) for
Serial ATA 3Gb/s.
USB 2.0 technology
USB 2.0 is the latest connectivity standard for next generation
components and peripherals. Backwards compatible with current USB
1.1 peripherals, USB 2.0 delivers transfer speeds up to 40 times faster
at 480Mb/s, for easy connectivity and ultra-fast data transfers.
Native DDR2 1066 support
This motherboard supports native DDR2 1066. It provides faster data
transfer rate and more bandwidth to increase memory computing
efciency, enhancing system performance in 3D graphics and other
memory demanding applications.
Serial ATA 3Gb/s technology and RAID support
This motherboard supports hard drives based on the Serial ATA
(SATA) 3Gb/s storage specications. It allows RAID 0, RAID 1, RAID
5, RAID 10, and JBOD congurations for Serial ATA drives.
Gigabit LAN solution
The on-board LAN controller is a highly integrated Gb LAN controller.
It is enhanced with an ACPI management function to provide efcient
power management for advanced operating systems.
1-2 ASUS M2N68-AM

1.3.2 Innovative ASUS features
ASUS Q-Fan technology
ASUS Q-Fan technology intelligently adjusts CPU fan speeds
according to system loading to ensure a quiet, cool, and efcient
operation.
ASUS CrashFree BIOS 3
ASUS CrashFree BIOS 3 is an auto-recovery tool that allows you to
restore a corrupted BIOS le using the bundled support DVD or USB
ash disk that contains the latest BIOS le.
ASUS EZ Flash 2
ASUS EZ Flash 2 is a utility that allows you to update the BIOS
without using an OS-based utility.
CPU Parameter Recall (C.P.R)
The BIOS C.P.R. feature automatically restores the CPU default
settngs when the system hangs due to overclocking failure. C.P.R.
eliminates the need to open the system chassis and clear the
RTC data. Simply shut down and reboot the system, and the BIOS
automatically restores the CPU parameters to their default settings.
ASUS MyLogo 2™
Turn your favorite photos into 256-color boot logos to personalize your
system.
Green ASUS
This motherboard and its packaging comply with the European
Union’s Restriction on the use of Hazardous Substances (RoHS). This
is in line with the ASUS vision of creating environment-friendly and
recyclable products and packaging to safeguard consumers’ health
while minimizing the impact on the environment.
Chapter 1: Product introduction 1-3

1.4 Before you proceed
Take note of the following precautions before you install motherboard components or change
any motherboard settings.
• Unplug the power cord from the wall socket before touching any component.
• Before handling components, use a grounded wrist strap or touch a safely grounded
object or a metal object, such as the power supply case, to avoid damaging them due to
static electricity.
• Hold components by the edges to avoid touching the ICs on them.
• Whenever you uninstall any component, place it on a grounded antistatic pad or in the
bag that came with the component.
• Before you install or remove any component, switch off the ATX power supply and
detach its power cord. Failure to do so may cause severe damage to the motherboard,
peripherals, or components.
Onboard LED
The motherboard comes with a standby power LED that lights up to indicate that the system
is ON, in sleep mode, or in soft-off mode. This is a reminder that you should shut down
the system and unplug the power cable before removing or plugging in any motherboard
component. The illustration below shows the location of the onboard LED.
M2N68-AM
SB_PWR
ON
Standby Power Powered Of
f
OFF
M2N68-AM Onboard LED
1-4 ASUS M2N68-AM

1.5 Motherboard overview
1.5.1 Placement direction
When installing the motherboard, ensure that you place it into the chassis in the correct
orientation. The edge with external ports goes to the rear part of the chassis as indicated in
the image below.
1.5.2 Screw holes
Place six screws into the holes indicated by circles to secure the motherboard to the chassis.
Do not overtighten the screws! Doing so can damage the motherboard.
Place this side towards
the rear of the chassis.
M2N68-AM
Chapter 1: Product introduction 1-5

1.5.3 Motherboard layout
1.5.4 Layout contents
M2N68-AM
PCIEX16
PCIEX1_1
PCI2
PCI1
PRI_IDE
FLOPPY USB56 USB78 USB910 F_PANEL
SPDIF_OUT
AAFP
CD
ATX12V
EATXPWR
CPU_FAN
Lithium Cell
CMOS Power
Super
I/O
ALC
662
RTL
8211CL
KBMS
8Mb
BIOS
SB_PWR
CLRTC
SPEAKER
22.2cm(8.75in)
24.4cm(9.6in)
Nvidia®
MCP68
Family
DDR2 DIMM_A1 (64bit, 240-pin module)
SOCKET AM2
DDR2 DIMM_B1 (64bit, 240-pin module)
SATA2SATA1
SATA4SATA3
VGA
AUDIO
LPT
COM
LAN1_USB12
USB34
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15 16
Connectors/Jumpers/Slots/LED Page Connectors/Jumpers/Slots/LED Page
1. ATX power connectors (24-pin EATXPWR, 4-pin ATX12V) 1-26 9. System panel connector (10-1 pin F_PANEL) 1-27
2. IDE connector (40-1 pin PRI_IDE) 1-21 10. Optical drive audio connector (4-pin CD) 1-24
3. CPU fan connector (4-pin CPU_FAN) 1-23 11. Front panel audio connector (10-1 pin AAFP) 1-25
4. Serial ATA connectors (7-pin SATA1, 2, 3, 4) 1-22 12. AM2 CPU Socket 1-7
5. USB connectors (10-1 pin USB56, USB 78, USB910) 1-24 13. DDR2 DIMM slots 1-10
6. Clear RTC RAM (3-pin CLRTC) 1-18 14. PCIe x16/PCIe x1/PCI slot 1-17
7. Internal speaker connector (4-pin SPEAKER) 1-25 15. Digital audio connector (4-1 pin SPDIF_OUT) 1-23
8. Standby power LED (SB_PWR) 1-4 16. Floppy disk drive connector (34-1 pin FLOPPY) 1-20
1-6 ASUS M2N68-AM

1.6 Central Processing Unit (CPU)
The motherboard comes with an AM2 / AM2+ socket designed for AMD® Phenom™ FX /
Phenom / Athlon™ / Sempron™ processor.
The AM2/AM2+ socket has a different pinout from the 940-pin socket designed for the AMD
Opteron™ processor. Use a CPU that is designed for the AM2/AM2+ socket.
1.6.1 Installing the CPU
To install a CPU:
1. Locate the CPU socket on the motherboard.
2. Press the lever sideways to unlock
the socket, then lift it up to a 90°-
100° angle. Socket lever
Ensure that the socket lever is lifted up to 90°-100° angle, otherwise the CPU will not t in
completely.
M2N68-AM
M2N68-AM CPU socket AM2
Chapter 1: Product introduction 1-7

3. Position the CPU above the socket such that the CPU
corner with the gold triangle matches the socket corner
with a small triangle.
4. Carefully insert the CPU into the socket until it ts in place.
The CPU ts only in one correct
orientation. DO NOT force the CPU into
the socket to prevent bending the pins
and damaging the CPU!
Gold triangle
Small triangle
5. When the CPU is in place, push down the socket
lever to secure the CPU. The lever clicks on the side
tab to indicate that it is locked.
6. Install a CPU heatsink and fan following the
instructions that came with the heatsink package.
You can also refer to section 1.6.2 Installing
heatsink and fan for instructions.
7. Connect the CPU fan cable to the CPU_FAN connector on the motherboard.
Do not forget to connect the CPU fan connector! Hardware monitoring errors can occur if
you fail to plug this connector.
CPU_FAN
GND CPU FAN PWR CPU FAN IN CPU FAN PWM
M2N68-AM
M2N68-AM CPU fan connector
1-8 ASUS M2N68-AM

1.6.2 Installing the heatsink and fan
Ensure that you use only AMD-certied heatsink and fan assembly.
To install the CPU heatsink and fan:
1. Place the heatsink on top of the installed CPU, making sure that the heatsink ts
properly on the retention module base.
• The retention module base is already installed on the motherboard upon purchase.
• You do not have to remove the retention module base when installing the CPU or
installing other motherboard components.
• If you purchased a separate CPU heatsink and fan assembly, ensure that a Thermal
Interface Material is properly applied to the CPU heatsink or CPU before you install the
heatsink and fan assembly.
CPU Fan
CPU Heatsink
Retention bracket
Retention bracket lock
Retention Module Base
Your boxed CPU heatsink and fan assembly should come with installation instructions for
the CPU, heatsink, and the retention mechanism. If the instructions in this section do not
match the CPU documentation, follow the latter.
2. Attach one end of the retention bracket to the retention module base.
1
34
5
2
Chapter 1: Product introduction 1-9

3. Align the other end of the retention bracket to the retention module base. A clicking
sound denotes that the retention bracket is in place.
Ensure that the fan and heatsink assembly perfectly ts the retention mechanism module
base, otherwise you cannot snap the retention bracket in place.
4. Push down the retention bracket lock on the retention mechanism to secure the
heatsink and fan to the module base.
5. When the fan and heatsink assembly is in place, connect the CPU fan cable to the
connector on the motherboard labeled CPU_FAN.
Do not forget to connect the CPU fan connector! Hardware monitoring errors can occur if
you fail to plug this connector.
1.7 System memory
1.7.1 Overview
The motherboard comes with two Double Data Rate 2 (DDR2) Dual Inline Memory Modules
(DIMM) sockets. A DDR2 module has the same physical dimensions as a DDR DIMM but
has a 240-pin footprint compared to the 184-pin DDR DIMM. DDR2 DIMMs are notched
differently to prevent installation on a DDR DIMM socket. The gure illustrates the location of
the DDR2 DIMM sockets:
Channel Sockets
Channel A DIMM_A1
Channel B DIMM_B1
M2N68-AM
M2N68-AM 240-pin DDR2 DIMM sockets
DIMM_A1 DIMM_B1
1-10 ASUS M2N68-AM