Intel BLKDH55TC User manual

Intel®Desktop Board DH55TC
Product Guide
Order Number: E78882-001

Revision History
Revision Revision History Date
-001 First release of the Intel®Desktop Board DH55TC Product Guide October 2009
If an FCC declaration of conformity marking is present on the board, the following statement applies:
FCC Declaration of Conformity
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.
For questions related to the EMC performance of this product, contact:
Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124
1-800-628-8686
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 the 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 the receiver.
•Connect the equipment to an outlet on a circuit other than the one to which the receiver is connected.
•Consult the dealer or an experienced radio/TV technician for help.
Any changes or modifications to the equipment not expressly approved by Intel Corporation could void the
user’s authority to operate the equipment.
Tested to comply with FCC standards for home or office use.
Canadian Department of Communications Compliance 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.
Le présent appareil numerique német pas de bruits radioélectriques dépassant les limites applicables aux
appareils numériques de la classe B prescrites dans le Réglement sur le broullage radioélectrique édicté par
le ministére des Communications du Canada.
Disclaimer
INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL®PRODUCTS. NO LICENSE,
EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS
GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN INTEL’S TERMS AND CONDITIONS OF SALE FOR
SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER, AND INTEL DISCLAIMS ANY EXPRESS OR
IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING LIABILITY OR
WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT
OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. Intel products are not intended
for use in medical, life saving, or life sustaining applications. Intel may make changes to specifications and
product descriptions at any time, without notice.
Intel Desktop Board DH55TC may contain design defects or errors known as errata which may cause the
product to deviate from published specifications. Current characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing
your product order.
Copies of documents which have an ordering number and are referenced in this document, or other Intel
literature, may be obtained from Intel Corporation by going to the World Wide Web site at:
http://www.intel.com/ or by calling 1-800-548-4725.
Intel is a trademark of Intel Corporation in the United States and other countries.
* Other names and brands may be claimed as the property of others.
Copyright © 2009, Intel Corporation. All rights reserved.

iii
Preface
This Product Guide gives information about board layout, component installation, BIOS
update, and regulatory requirements for Intel®Desktop Board DH55TC.
Intended Audience
The Product Guide is intended for technically qualified personnel. It is not intended for
general audiences.
Use Only for Intended Applications
All Intel Desktop Boards are evaluated as Information Technology Equipment (I.T.E.)
for use in personal computers (PC) for installation in homes, offices, schools, computer
rooms, and similar locations. The suitability of this product for other PC or embedded
non-PC applications or other environments, such as medical, industrial, alarm systems,
test equipment, etc. may not be supported without further evaluation by Intel.
Document Organization
The chapters in this Product Guide are arranged as follows:
1 Desktop Board Features: a summary of product features
2 Installing and Replacing Desktop Board Components: instructions on how to install
the Desktop Board and other hardware components
3 Updating the BIOS: instructions on how to update the BIOS
A Error Messages and Indicators: information about BIOS error messages and beep
codes
B Regulatory Compliance: describes the board’s adherence to safety standards and
EMC regulations and its product certifications
Conventions
The following conventions are used in this manual:
CAUTION
Cautions warn the user about how to prevent damage to hardware or loss of data.
NOTE
Notes call attention to important information.

Intel Desktop Board DH55TC Product Guide
iv
Terminology
The table below gives descriptions of some common terms used in the product guide.
Term Description
GB Gigabyte (1,073,741,824 bytes)
GHz Gigahertz (one billion hertz)
KB Kilobyte (1024 bytes)
MB Megabyte (1,048,576 bytes)
Mb Megabit (1,048,576 bits)
MHz Megahertz (one million hertz)

v
Contents
1Desktop Board Features
Supported Operating Systems..............................................................................11
Desktop Board Components.................................................................................12
Processor..........................................................................................................14
Intel®H55 Express Chipset .................................................................................14
Main Memory.....................................................................................................15
Graphics Subsystem...........................................................................................15
Integrated Graphics ....................................................................................15
Analog Display (VGA)...........................................................................15
High-Definition Multimedia Interface* (HDMI*)........................................16
Digital Visual Interface (DVI-D) .............................................................16
PCI Express* x16 Graphics ..........................................................................16
Audio Subsystem ...............................................................................................16
LAN Subsystem .................................................................................................17
USB 2.0 Support................................................................................................18
Serial ATA Support.............................................................................................18
Expandability.....................................................................................................18
Legacy I/O........................................................................................................19
BIOS................................................................................................................19
Serial ATA Auto Configuration.......................................................................19
PCI*/PCI Express Auto Configuration.............................................................19
Security Passwords.....................................................................................19
Hardware Management .......................................................................................20
Hardware Monitoring and Fan Speed Control ..................................................20
Fan Monitoring ...........................................................................................20
Power Management............................................................................................21
Software Support .......................................................................................21
ACPI..................................................................................................21
Hardware Support ......................................................................................21
Power Connectors ...............................................................................21
Fan Headers .......................................................................................21
LAN Wake Capabilities..........................................................................22
Instantly Available PC Technology..........................................................22
+5 V Standby Power Indicator LED ........................................................23
Wake from USB ..................................................................................23
PCI PME# Signal Wake-up Support ........................................................23
PCI Express WAKE# Signal Wake-up Support..........................................24
Wake from PS/2 Devices ......................................................................24
Wake from Serial Port..........................................................................24
ENERGY STAR*, e-Standby, and ErP Compliance.............................................24
Speaker............................................................................................................24
Real-Time Clock Subsystem.................................................................................25

Intel Desktop Board DH55TC Product Guide
vi
2Installing and Replacing Desktop Board Components
Before You Begin ...............................................................................................27
Installation Precautions.......................................................................................28
Prevent Power Supply Overload ....................................................................28
Observe Safety and Regulatory Requirements.................................................28
Installing the I/O Shield ......................................................................................29
Installing and Removing the Desktop Board ...........................................................30
Installing and Removing a Processor.....................................................................31
Installing a Processor ..................................................................................31
Installing a Processor Fan Heat Sink..............................................................36
Connecting the Processor Fan Heat Sink Cable................................................36
Removing the Processor ..............................................................................36
Installing and Removing System Memory ..............................................................37
Guidelines for Dual Channel Memory Configuration..........................................37
Two or Four DIMMs .............................................................................37
Three DIMMs ......................................................................................38
Installing DIMMs ........................................................................................39
Removing DIMMs........................................................................................41
Installing and Removing PCI Express x16 Graphics Cards.........................................41
Installing a PCI Express x16 Graphics Card ....................................................41
Removing a PCI Express x16 Graphics Card....................................................42
Connecting Serial ATA (SATA) Cables....................................................................44
Installing an Intel®Z-U130 USB Solid-State Drive (or Compatible Device)..................45
Connecting to the Internal Headers ......................................................................46
Front Panel Audio Header ............................................................................47
Internal Mono Speaker Header .....................................................................47
S/PDIF Header ...........................................................................................48
Parallel Port Header ....................................................................................48
Alternate Front Panel Power LED Header ........................................................49
Front Panel Header .....................................................................................49
Front Panel USB 2.0 Headers........................................................................50
Serial Header.............................................................................................51
Connecting to the Audio System...........................................................................51
Connecting Chassis Fan and Power Supply Cables...................................................52
Connecting Chassis Fan Cables .....................................................................52
Connecting Power Supply Cables ..................................................................53
Setting the BIOS Configuration Jumper .................................................................54
Clearing Passwords ............................................................................................55
Replacing the Battery .........................................................................................56
3Updating the BIOS
Updating the BIOS with the Intel®Express BIOS Update Utility.................................63
Updating the BIOS with the ISO Image BIOS Update File or the Iflash
Memory Update Utility...................................................................................64
Obtaining the BIOS Update File ....................................................................64
Updating the BIOS with the ISO Image BIOS Update File .................................64
Updating the BIOS with the Iflash Memory Update Utility .................................65
Recovering the BIOS...................................................................................66

Contents
vii
AError Messages and Indicators
BIOS Error Codes...............................................................................................67
BIOS Error Messages..........................................................................................68
BRegulatory Compliance
Safety Standards ...............................................................................................69
Place Battery Marking .................................................................................69
European Union Declaration of Conformity Statement..............................................70
Product Ecology Statements ................................................................................71
Recycling Considerations .............................................................................71
Lead-free 2LI/Pb-free 2LI Board ...................................................................74
Restriction of Hazardous Substances (RoHS) ..................................................75
EU RoHS ............................................................................................75
China RoHS ........................................................................................76
EMC Regulations ................................................................................................78
Ensure Electromagnetic Compatibility (EMC) Compliance..................................79
Product Certifications..........................................................................................80
Board-Level Certification Markings ................................................................80
Chassis and Component Certifications............................................................81
Figures
1. Intel Desktop Board DH55TC Components........................................................12
2. LAN Connector LEDs .....................................................................................17
3. Location of the Standby Power Indicator ..........................................................23
4. Installing the I/O Shield ................................................................................29
5. Intel Desktop Board DH55TC Mounting Screw Hole Locations..............................30
6. Unlatch the Socket Lever...............................................................................31
7. Lift the Load Plate.........................................................................................32
8. Remove the Socket Cover..............................................................................33
9. Remove the Processor from the Protective Cover ..............................................34
10. Install the Processor .....................................................................................34
11. Lower the Load Plate.....................................................................................35
12. Secure the Load Plate in Place........................................................................35
13. Connecting the Processor Fan Heat Sink Power Cable
to the Processor Fan Header ..........................................................................36
14. Example Dual Channel Memory Configuration with Two DIMMs ...........................37
15. Example Dual Channel Memory Configuration with Four DIMMs...........................38
16. Example Dual Channel Memory Configuration with Three DIMMs .........................38
17. Use DDR3 DIMMs .........................................................................................39
18. Installing a DIMM .........................................................................................40
19. Installing a PCI Express x16 Graphics Card ......................................................42
20. Removing a PCI Express x16 Graphics Card......................................................43
21. Connecting a Serial ATA Cable........................................................................44
22. Installing an Intel Z-U130 USB Solid-State Drive (or Compatible Device)..............45
23. Internal Headers ..........................................................................................46
24. Back Panel Audio Connectors .........................................................................51
25. Location of the Chassis Fan Headers................................................................52
26. Connecting Power Supply Cables ....................................................................53
27. Location of the BIOS Configuration Jumper Block ..............................................54
28. Removing the Battery ...................................................................................61
29. Intel Desktop Board DH55TC China RoHS Material Self Declaration Table..............77

Intel Desktop Board DH55TC Product Guide
viii
Tables
1. Feature Summary.......................................................................................... 9
2. Intel Desktop Board DH55TC Components........................................................13
3. LAN Connector LEDs .....................................................................................18
4. Front Panel Audio Signal Names for Intel HD Audio............................................47
5. Front Panel Audio Header Signal Names for AC ’97 Audio ...................................47
6. Internal Mono Speaker Header .......................................................................47
7. S/PDIF Header Signal Names .........................................................................48
8. Parallel Port Header ......................................................................................48
9. Alternate Front Panel Power LED Header Signal Names ......................................49
10. Front Panel Header Signal Names ...................................................................49
11. Front Panel USB Header (with Intel Z-U130 USB Solid-State Drive
(or Compatible Device) Support) Signal Names.................................................50
12. USB 2.0 Header Signal Names........................................................................50
13. Serial Port Header ........................................................................................51
14. Jumper Settings for the BIOS Setup Program Modes..........................................55
15. BIOS Beep Codes .........................................................................................67
16. Front-panel Power LED Blink Codes .................................................................68
17. BIOS Error Messages ....................................................................................68
18. Safety Standards..........................................................................................69
19. Lead-Free Second Level Interconnect Marks .....................................................75
20. China RoHS Environmentally Friendly Use Period Mark .......................................76
21. EMC Regulations...........................................................................................78
22. Product Certification Markings ........................................................................80

9
1 Desktop Board Features
This chapter briefly describes the features of Intel®Desktop Board DH55TC. Table 1
summarizes the major features of the Desktop Board.
Table 1. Feature Summary
Form Factor MicroATX (243.84 millimeters [9.60 inches] x 243.84 millimeters
[9.60 inches])
Processor •Intel®Core™ i7, Intel®Core™ i5, Intel®Core™ i3 and Intel®
Pentium processors in an LGA1156 socket:
―Integrated graphics processing (processors with Intel®Graphics
Technology)
―External graphics interface controller
―Integrated memory controller
Chipset Intel®H55 Express Chipset consisting of the Intel®H55 Express
Platform Controller Hub (PCH)
Memory •Four 240-pin DDR3 SDRAM Dual Inline Memory Module (DIMM)
sockets
•Support for DDR3 1333 MHz and DDR3 1066 MHz DIMMs
•Support for 1 Gb and 2 Gb memory technology
•Support for up to 16 GB of system memory with four DIMMs using
2 Gb memory technology
•Support for non-ECC memory
Graphics •Integrated graphics support for processors with Intel Graphics
Technology:
―VGA
―High-Definition Multimedia Interface* (HDMI*)
―DVI-D
•Discrete graphics support for PCI Express* 2.0 x16 add-in graphics
card
Audio Intel®High Definition Audio via the Realtek* ALC888S audio codec and
the HDMI interface
Expansion
Capabilities
•One PCI Express 2.0 x16 add-in card connector
•Two PCI Express 2.0 x1 add-in card connectors
•One PCI* bus connector
continued

Intel Desktop Board DH55TC Product Guide
10
Table 1. Feature Summary (continued)
Peripheral
Interfaces
•Twelve USB 2.0 ports:
―Six ports are implemented with stacked back panel connectors
―Six ports are implemented with three dual-port internal
headers; one header supports an Intel Z-U130 USB Solid-State
Drive (or compatible device)
•Six Serial ATA (SATA) 3.0 Gb/s ports, two ports compatible with
eSATA adapters
•One serial port header
•One parallel port header
•One PS/2 back panel connector
LAN Support Intel®82578DC Gigabit (10/100/1000 Mb/s) Ethernet LAN controller
including an RJ-45 back panel connector with integrated status LEDs
BIOS •Intel®BIOS resident in an SPI Flash device
•Support for Advanced Configuration and Power Interface (ACPI),
Plug and Play, and SMBIOS
Instantly Available
PC Technology
•Support for PCI Local Bus Specification Revision 2.2
•Support for PCI Express Base Specification Revision 2.0
•Suspend to RAM support
•Wake on PCI, PCI Express, LAN, front panel, PS/2, serial, and USB
ports
Hardware
Management
•Intel®Quiet System Technology (Intel®QST) implemented through
the Intel®Management Engine (Intel®ME) in the H55 PCH
•Voltage sense to detect out of range power supply voltages
•Thermal sense to detect out of range thermal values
•Three fan headers using PWM control
•4-pin headers for processor, front, and rear fans
•4-wire and 3-wire (linear) fan speed control support for front and
rear fans
•Support for Platform Environmental Control Interface (PECI)

Desktop Board Features
11
Supported Operating Systems
The Desktop Board supports the following operating systems:
•Microsoft Windows* 7 Ultimate 64-bit edition
•Microsoft Windows 7 Ultimate 32-bit edition
•Microsoft Windows 7 Home Premium 64-bit edition
•Microsoft Windows 7 Home Premium 32-bit edition
•Microsoft Windows 7 Home Basic 64-bit edition
•Microsoft Windows 7 Home Basic 32-bit edition
•Microsoft Windows Vista* Ultimate 32-bit edition
•Microsoft Windows Vista Business 32-bit edition
•Microsoft Windows Vista Home Premium 32-bit edition
•Microsoft Windows Vista Home Basic 32-bit edition
•Microsoft Windows Vista Ultimate 64-bit edition
•Microsoft Windows Vista Business 64-bit edition
•Microsoft Windows Vista Home Premium 64-bit edition
•Microsoft Windows Vista Home Basic 64-bit edition
•Microsoft Windows* XP Media Center Edition 2005
•Microsoft Windows XP Professional
•Microsoft Windows XP Professional x64 Edition
•Microsoft Windows XP Home

Intel Desktop Board DH55TC Product Guide
12
Desktop Board Components
Figure 1 shows the approximate location of the major components on Intel Desktop
Board DH55TC.
Figure 1. Intel Desktop Board DH55TC Components

Desktop Board Features
13
Table 2. Intel Desktop Board DH55TC Components
Label Description
A PCI bus add-in card connector
B PCI Express 2.0 x1 add-in card connector
C Battery
D PCI Express 2.0 x1 add-in card connector
E PCI Express 2.0 x16 add-in card connector
F Back panel connectors
G 12 V processor core voltage connector (2 x 2 pin)
H Rear chassis fan header
I Processor socket
J Processor fan header
K DDR3 Channel A, DIMM 0 and DIMM 1 sockets
L DDR3 Channel B, DIMM 0 and DIMM 1 sockets
M Front chassis fan header
N Main power connector (2 x 12 pin)
O Serial ATA connectors (6)
P BIOS configuration jumper block
Q Alternate front panel power LED header
R Front panel header
S Standby power indicator LED
T Front panel USB header with support for an Intel Z-U130 USB Solid-State
Drive (or compatible device)
U Front panel USB 2.0 headers (2)
V Parallel port header
W Speaker
X Serial port header
Y S/PDIF header
Z Front panel audio header
AA Internal mono speaker header

Intel Desktop Board DH55TC Product Guide
14
Online Support
For more information on Intel Desktop Board DH55TC consult the following online
resources:
•Intel Desktop Board DH55TC http://www.intel.com/products/motherboard/DH55TC/
index.htm
•Desktop Board Support http://support.intel.com/support/motherboards/deskt
op/DH55TC
•Available configurations for Intel
Desktop Board DH55TC
http://www.intel.com/products/motherboard/DH55TC/
index.htm
•Supported processors http://processormatch.intel.com
•Chipset information http://www.intel.com/products/desktop/chipsets/inde
x.htm
•BIOS and driver updates http://downloadcenter.intel.com/
•Integration information http://www.intel.com/support/go/buildit
Processor
CAUTION
Failure to use an appropriate power supply and/or not connecting the 12 V (2 x 2 pin)
power connector to the Desktop Board may result in damage to the board, or the
system may not function properly.
Intel Desktop Board DH55TC supports the Intel Core i7, and Intel Core i5, Intel
Core i3, and Intel Pentium processors in an LGA1156 socket. Processors are not
included with the Desktop Board and must be purchased separately. The processor
connects to the Desktop Board through the LGA1156 socket.
For information on supported processors for Intel Desktop Board DH55TC, go to
http://processormatch.intel.com.
Intel®H55 Express Chipset
The Intel H55 Express Chipset, consisting of the Intel H55 Platform Controller Hub
(PCH), provides interfaces to the processor and the USB, SATA, LPC, audio, network,
display, PCI, and PCI Express x1 interfaces. The PCH is a centralized controller for the
board’s I/O paths.

Desktop Board Features
15
Main Memory
NOTE
To be fully compliant with all applicable Intel
®SDRAM memory specifications, the
board should be populated with DIMMs that support the Serial Presence Detect (SPD)
data structure. If your memory modules do not support SPD, you will see a
notification to this effect on the screen at power up. The BIOS will attempt to
configure the memory controller for normal operation.
The board has four DIMM sockets and supports the following memory features:
•Two independent memory channels with interleaved mode support
•Support for non-ECC, unbuffered, single-sided or double-sided DIMMs with x8
organization
•16 GB maximum total system memory (with 2 Gb memory technology)
•Minimum total system memory: 1 GB using 1 Gb x8 module
•Serial Presence Detect
•DDR3 1333 MHz and DDR3 1066 MHz SDRAM DIMMs
NOTE
32-bit operating systems are limited to a maximum of 4 GB of memory. These
operating systems will report less than 4 GB because of the memory used by
add-in graphics cards and other system resources.
NOTE
When using a processor without Intel Graphics Technology, memory must be installed
in either or both of the DIMM 0 (blue) memory sockets for the system to boot.
Graphics Subsystem
The board supports either integrated graphics (Intel Graphics Technology) or PCI
Express 2.0 x16 graphics.
Integrated Graphics
The board supports integrated graphics through the Intel Flexible Display Interface
(FDI) for processors with Intel Graphics Technology.
Analog Display (VGA)
The VGA port supports analog displays. The maximum supported resolution is 2048 x
1536 (QXGA) at a 75 Hz refresh rate.
The VGA port is enabled for the POST whenever a monitor is attached, regardless of
the HDMI and DVI connector status.

Intel Desktop Board DH55TC Product Guide
16
High-Definition Multimedia Interface* (HDMI*)
The HDMI port supports standard, enhanced, or high-definition video, plus multi-
channel digital audio on a single cable. It is compatible with all ATSC and DVB HDTV
standards and supports 8-channel digital audio. The maximum supported resolution is
1920 x 1200 at 60 Hz refresh (WUXGA). The HDMI port is compliant with the
HDMI 1.3 specification.
The HDMI port is enabled for the POST whenever a monitor is attached, regardless of
the VGA and DVI connector status.
Digital Visual Interface (DVI-D)
The DVI-D port supports digital DVI displays. The maximum supported resolution is
1920 x 1200 at 60 Hz refresh (WUXGA). The DVI-D port is compliant with the DVI 1.0
specification.
The DVI-D port is only enabled for POST when there are no monitors attached to the
VGA or HDMI connectors.
PCI Express* x16 Graphics
The Intel Core i7, Intel Core i5, Intel Core i3, and Intel Pentium processors in an
LGA1156 socket support discrete add-in graphics cards via the PCI Express 2.0 x16
add-in card connector. The board supports the following PCI Express speeds:
•PCI Express GEN2 frequency of 2.5 GHz which results in 5.0 Gb/s in each direction
(500 MB/s) per lane. The maximum theoretical bandwidth on the interface is
8 GB/s in each direction, simultaneously, when operating in x16 mode.
•PCI Express GEN1 frequency of 1.25 GHz resulting in 2.5 Gb/s each direction
(250 MB/s) per lane. The maximum theoretical bandwidth on the interface is
4 GB/s in each direction, simultaneously, when operating in x16 mode.
Audio Subsystem
The board supports Intel High Definition Audio through a Realtek ALC888S audio codec
as well as through the HDMI interface.
The Realtek ALC888S-based audio subsystem provides the following features:
•Advanced jack sense for the back panel audio connectors that enables the audio
codec to recognize the device that is connected to an audio port. The back panel
audio connectors are capable of retasking according to the user’s definition, or can
be automatically switched depending on the recognized device type.
•Stereo input and output via back panel connectors
•Headphone and Mic in functions for front panel audio connectors
•A signal-to-noise (S/N) ratio of 90 dB
The board provides onboard audio headers and back panel connectors.

Desktop Board Features
17
The onboard audio headers include the following:
•Front panel audio (a 2 x 5 pin header that provides headphone and mic in signals
for front panel audio connectors)
•S/PDIF audio header (1 x 4 pin header)
•Internal mono speaker header (1 x 2 pin header)
Front panel headphone output is supported by a separate audio channel pair, allowing
multi-streaming audio configurations such as simultaneous 6-channel (5.1) surround
sound playback and stereo audio conferencing (through speakers connected to the
back panel audio connectors and a headset connected to front panel audio
connectors).
The onboard internal mono speaker header allows connection to an internal, low-
power speaker for basic system sound capability. The subsystem is capable of driving
a target speaker load of 8 Ωat 1 W (rms) or 4 Ωat 1.5 W (rms).
The onboard S/PDIF header allows connection to coaxial or optical adapters for digital
audio output.
The back panel audio connectors (see Figure 24 on page 51) are configurable through
the audio device drivers. Audio software and drivers are available from
http://downloadcenter.intel.com/.
LAN Subsystem
The LAN subsystem includes:
•Intel 82578DC Gigabit (10/100/1000 Mb/s) Ethernet LAN controller
•RJ-45 LAN connector with integrated status LEDs
LAN software and drivers are available at http://downloadcenter.intel.com/.
Two LEDs are built into the RJ-45 LAN connector located on the back panel (see
Figure 2). These LEDs indicate the status of the LAN as shown in Table 3.
Figure 2. LAN Connector LEDs

Intel Desktop Board DH55TC Product Guide
18
Table 3. LAN Connector LEDs
LED LED Color LED State Indicates
A (Link/Activity) Off LAN link is not established
Green
On LAN link is established
Blinking LAN activity is occurring
N/A Off 10 Mb/s data rate
Green On 100 Mb/s data rate
B (Link Speed)
Yellow On 1000 Mb/s data rate
USB 2.0 Support
The board supports up to twelve USB 2.0 ports provided by two EHCI host controllers
in the PCH that allow the use of EHCI-compatible drivers.
The port arrangement is as follows:
•Six ports via stacked back panel connectors
•Six front panel ports via three dual-port internal headers; one header supports an
Intel Z-U130 USB Solid-State Drive (or compatible device)
USB 2.0 support requires both an operating system and drivers that fully support
USB 2.0 transfer rates.
Serial ATA Support
The board provides six internal SATA connectors through the PCH, four for internal
storage (black connectors) and two for internal as well as external SATA (eSATA)
storage (red connectors).
Expandability
Intel Desktop Board DH55TC provides the following expansion capability:
•One PCI Express 2.0 x16 port
•Two PCI Express 2.0 x1 ports
•One PCI bus interface

Desktop Board Features
19
Legacy I/O
The board’s Legacy I/O Controller provides the following legacy features:
•One serial port header
•One parallel port header with Extended Capabilities Port (ECP) and Enhanced
Parallel Port (EPP) support
•Serial IRQ interface compatible with serialized IRQ support for PCI Conventional
bus systems
•PS/2-style keyboard/mouse interface
•Intelligent power management, including a programmable wake-up event interface
•PCI Conventional bus power management support
The BIOS Setup program provides configuration options for the Legacy I/O controller.
BIOS
The BIOS provides the Power-On Self-Test (POST), the BIOS Setup program, and the
PCI Express and SATA auto-configuration utilities. The BIOS is stored in the Serial
Peripheral Interface (SPI) Flash device.
The BIOS can be updated by following the instructions in Chapter 3 starting on
page 63.
Serial ATA Auto Configuration
If you install a Serial ATA device (such as a hard drive) in your computer, the auto-
configuration utility in the BIOS automatically detects and configures the device for
your computer. You do not need to run the BIOS Setup program after installing a
Serial ATA device. You can override the auto-configuration options by specifying
manual configuration in the BIOS Setup program.
PCI*/PCI Express Auto Configuration
If you install a PCI or PCI Express add-in card in your computer, the PCI/PCI Express
auto-configuration utility in the BIOS automatically detects and configures the
resources (IRQs, DMA channels, and I/O space) for that add-in card. You do not need
to run the BIOS Setup program after you install a PCI or PCI Express add-in card.
Security Passwords
The BIOS includes security features that restrict whether the BIOS Setup program can
be accessed and who can boot the computer. A supervisor password and a user
password can be set for the BIOS Setup and for booting the computer, with the
following restrictions:
•The supervisor password gives unrestricted access to view and change all Setup
options. If only the supervisor password is set, pressing <Enter> at the password
prompt of Setup gives the user restricted access to Setup.

Intel Desktop Board DH55TC Product Guide
20
•If both the supervisor and user passwords are set, you must enter either the
supervisor password or the user password to access Setup. Setup options are then
available for viewing and changing depending on whether the supervisor or user
password was entered.
•Setting a user password restricts who can boot the computer. The password
prompt is displayed before the computer is booted. If only the supervisor
password is set, the computer boots without asking for a password. If both
passwords are set, you can enter either password to boot the computer.
For instructions on resetting the password, go to Clearing Passwords on page 55.
Hardware Management
The hardware management features of Intel Desktop Board DH55TC enable the board
to be compatible with the Wired for Management (WfM) specification. The board has
several hardware management features including the following:
•Fan speed monitoring and control
•Thermal and voltage monitoring
Hardware Monitoring and Fan Speed Control
The features of the hardware monitoring and fan speed control include:
•Intel Quiet System Technology, delivering acoustically-optimized thermal
management
•Thermal sensors in the processor and PCH, as well as near the CPU voltage
regulators and system memory
•Monitoring of system voltages to detect levels above or below acceptable values
•Thermally monitored closed-loop fan control for all three fans that can adjust fan
speed as needed
Fan Monitoring
Fan monitoring can be observed via the BIOS Setup program, Intel®Desktop Utilities,
or third-party software.