HP Compaq dc7900 Service and Maintain

Illustrated Parts & Service Map

HP Compaq dc7900 Ultra Slim Desktop
Business PC

© 2008, 2009, 2010 Hewlett-Packard Development Company, L.P. The infor-

mation contained herein is subject to change without notice. HP shall not be
liable for technical or editorial errors or omissions contained herein. Intel,
Pentium, Intel Inside, and the Intel logo are trademarks or registered trade-

tries.

Document Number 506595-003. 3rd Edition June 2010.

Key Specifications

Processor Type Intel Celeron, Pentium Dual-Core, Core2 Duo, Core2 Quad

RAM Type DDR2-SODIMMs, PC2 6400 (800 MHz) non-ECC

Maximum RAM Supported 4 GB

Expansion Slots PCI Express Mini Card

Graphics Adapter Integrated Intel GMA 3200 graphics

Drive Support • 1 hard drive, 2.5-inch

I/O Interfaces USB 2.0 (8), USB 2.0, internal on system board (2), RJ-45 (1),

Spare Parts

marks of the Intel Corporation and its subsidiaries in the U. S. and other coun-

• 1 Slimline optical

• 1 mini PCIe solid state drive

front and rear audio jacks (2 each), PS/2 ports (2), VGA/DVI­D connector

Cable and accessory

1 Optical drive cable/connector 499201-001

* Cable cover 451397-001

* Not shown

Keyboards (not illustrated)

PS/2, Basic
USB, Basic
USB SmartCard

Arabic -171 LA Spanish -161

Belgian -181 Norwegian -091

BHCSY -B41

Brazilian Portuguese -201 Portuguese -131

Czech -221 Romanian -271

Danish -081

Finnish -351 Saudi Arabia* -DE1

French -051 Slovakian -231

French Canadian -121

German -041 Spanish -071

Greek -151 Swedish -101

Hebrew -BB1 Swiss -111

Hungarian -211 Taiwanese -AB1

International -B31 Thai -281

International English -L31

Italian -061 U.S. -001

Japanese -291 U.K. -031

*For 435385-xxx only

435302-xxx
435382-xxx
435385-xxx

People’s Republic of China

Russian -251

South Korea -KD1

Turkish -141

-AA1

System Unit

1 Access panel 497738-001

2 Front bezel 451388-001

3 Chassis not spared

4 AC adapter, 135W 482133-001

* Stand 451396-001

* Bezel blank 451394-001

* Not shown

Mass Storage Devices

1 DVD-ROM drive 494353-001

* DVD±RW and CD-RW Super Multi Double-Layer Combo Drive with

LightScribe

* DVD±RW and CD-RW Combo Drive 485604-001

* 250 GB, 7200 RPM hard drive 497730-001

2 160 GB, 7200 RPM hard drive 497729-001

* 80 GB hard drive 497728-001

485603-001

dc7900 Illustrated Parts & Service Map, USDT Chassis 506595-003 page 1

Standard and Optional Boards

System boards with thermal grease, alcohol pad, and CPU socket cover

1 System board 462433-001

* System board, excludes ES/CS 490631-001

Memory modules (SODIMM, PC2-6400, CL6)

*4 GB

*2 GB

21 GB

* 512 MB

Other boards

* Quadro NVS295 256-MB PCIe graphics card 519298-001

* 802.11a/b/g/n WLAN module (include card, antenna, cable, and screw) 502482-001

Intel Celeron Processors with alcohol pad and thermal grease

* 450, 2.2 GHz, 512-KB cache, single core 508256-001

* 440, 2.0 GHz, 512-KB cache, single core 449166-001

* E1500, 2.2 GHz, 512-MB cache, dual core 516899-001

* E1400, 2.0 GHz, 512-MB cache, dual core 491574-001

* E1200, 1.6 GHz, 512-MB cache, dual core 468589-001

Intel Pentium Dual Core Processors with alcohol pad and thermal grease

* E5400, 2.7 GHz, 2-MB L2 cache 531989-001

* E5200, 2.5 GHz, 2-MB L2 cache 503382-001

* E2220, 2.4 GHz, 1-MB L2 cache 480714-001

* E2200, 2.2 GHz, 1-MB L2 cache 465216-001

Intel Core 2 Duo Processors with alcohol pad and thermal grease

* E8600, 3.33 GHz, 6-MB L2 cache 497732-001

* E8500, 3.16 GHz, 6-MB L2 cache 466170-001

* E8400, 3.00 GHz, 6-MB L2 cache 509554-001

* E8300, 2.83 GHz, 6-MB L2 cache 466168-001

* E7500, 2.93 GHz, 3-MB L2 cache 531988-001

* E7400, 2.80 GHz, 3-MB L2 cache 508255-001

* E7300, 2.66 GHz, 3-MB L2 cache 500134-001

* E7200, 2.53 GHz, 3-MB L2 cache 490507-001

* E5300, 2.60 GHz, 2-MB L2 cache 516900-001

* Not shown

497739-001

451400-001

570027-001

571246-001

Miscellaneous Parts

1 Chassis fan with duct 451392-001

2 Chassis fan, rear 499202-001

3 Internal speaker 447085-001

4 Heatsink with alcohol pad and factory-applied thermal grease 490814-001

* USB powered speakers 466618-001

* Mouse, PS2, optical 417966-001

* Mouse, optical 390938-001

* Mouse, laser 459821-001

* Rubber feet, snap in 499204-001

* Hood sensor 392417-001

*Not shown

System Board

System Board Connectors and Jumpers (position of some untitled
components may vary in location)

E49 Password P11 Auxiliary audio connector

J9 Stacked RJ-45/Dual USB P54 Primary serial port

J10 Quad stacked USB P60 First SATA connector

J64 Display port connector P61 Second SATA connector

J68

Stacked keyboard/mouse connector

J69 Video connector P150

J70 Primary single USB port P151

J71 Secondary single USB port P160

J72 Microphone jack SW1 System front power button

J75 Headphone jack SW50 Clear CMOS

J78 Double stacked line-out/line-in XBT1 Real-time-clock battery

J103 DC power input XMM1 DIMM 1

J105 PCIe Mini Card XMM3 DIMM 3

P6 Internal speaker XU1 Processor

P9 Chassis fan

P125 Hood sensor

Media reader

ReadyBoost

SATA power header

dc7900 Illustrated Parts & Service Map, USDT Chassis 506595-003 page 2

System Setup and Boot

Basic system information regarding system information, setup, power management, hardware,
and passwords is maintained in the Setup Utility held in the system ROM. The Setup Utility is
accessed by pressing the F10 key when prompted (on screen) to do so during the boot sequence.
If the screen prompt opportunity is missed, a restart will be necessary. For more information
about Setup Utilities refer to the Service Reference Guide.

Computer Setup Menu

Heading Option/Description

File System Information - Lists the following main system specifications:

• Product name

• SKU number (some models)

• Processor type/speed/stepping

• Cache size (L1/L2)

• Memory size/speed/channels

• Integrated MAC Address

About - Displays copyright notice.

Set Time and Date - Allows you to set system time and date.

Flash System ROM - Allows you to select a drive containing a new BIOS.

Replicated Setup - Save to Rmv Media and Restore from Rmv Media

Default Setup

• Save Current Settings as Default

• Restore Factory Settings as Default

Apply Defaults and Exit - Applies the selected default settings and clears
any established passwords.

Ignore Changes and Exit - Exits Computer setup without saving changes.

Save Changes and Exit - Saves changes to system configuration or default
settings and exits Computer Setup.

Storage Device Configuration - Lists all installed BIOS-controlled storage devices.

Security Setup Password - Allows you to set and enable the setup (Administrator)

Power OS Power Management - Allows you to enable/disable Runtime Power

Advanced Power-On Options - Allows you to set:

The following options are available:

• Diskette Type(Legacy Diskettes only)-3.5” 1.44 MB and 5.25” 1.2 MB

• Drive Emulation

• Emulation Type - ATAPI Zip drive, hard disk, legacy diskette, CD-ROM
drive, and ATAPI LS-120 drive

• Multisector Transfers

• Translation Mode

• Translation Parameters

• SATA Default Values

Storage Options

• Removable Media Boot

• Legacy Diskette Write

• SATA Emulation

• Max eSATA Speed

DPS Self-Test - Allows you to execute self-tests on ATA hard drives.

Boot Order - Allows you to specify boot order.

• Shortcut to Temporarily Override Boot Order

password.

Power-On Password - Allows you to set and enable power-on password.

Password Options - When any password exists allows you to lock legacy
resources, enable/disable network server mode, specify password require­ment for warm boot, and allows you to enable/disable Setup Browse Mode.

Smart Cover (some models) - Allows you to lock/unlock cover lock and set
status of cover removal sensor.

Device Security (some models) - Enables/disables all I/O ports, audio, net­work controllers, SMBus controller, and embedded security devices.

USB Security - Allows you to set Device Available/Device Hidden for front
USB ports 3-6, rear USB ports 7-12, internal USB ports 1-2.

Network Service Boot - Enables/disables boot from OS on a server.

System IDs - Allows you to set Asset tag, ownership tag, Chassis serial
number, UUID, and keyboard locale setting.

DriveLock Security - Allows you to assign/modify a hard drive password for
added security.

System Security (some models) - Allows you to enable/disable:

• Data Execution Prevention

• Virtualization Technology

• Virtualization Technology Directed I/O

• Trusted Execution Technology

• Embedded Security Device Support

• OS management of Embedded Security Device through OS

• Smart Card BIOS Password Support

• PAVP (Protect Audio Video Path) (some models)

Setup Security Level - Provides method to allow users limited access to
change specified setup options without knowing Setup password.

Management, Idle Power Savings, ACPI S3 Hard Disk Reset, ACPI S3 PS2
Mouse Wakeup, USB Wake on Device Insertion (some models), Unique
Sleep State Blink Rates.

Hardware Power Management - Allows you to enable/disable SATA bus
power management.

Thermal - Allows you to control minimum permitted fan idle speed.

• POST mode - QuickBoot, FullBoot, or FullBoot every 1-30 days.

• POST messages - Enable/disable

• MEBx Setup prompt - Enable/disable or hidden/displayed

• F9 prompt - Enable/disable

• F10 prompt - Enable/disable

• F12 prompt - Enable/disable

• Factory Recovery Boot Support - Enable/disable

• Option ROM prompt - Enable/disable

• WOL After Power Loss - Enable/disable

• Remote wakeup boot source - Remote server/local hard drive

• After Power Loss - Off/on/previous state

• POST delay - None, 5, 10, 15, or 20 seconds

• Limit CPUID Maximum value to 3

Execute Memory Test (some models) -Restarts computer and executes
POST memory test.

BIOS Power-On - Allows you to set the computer to turn on at a preset time.

Onboard Devices - Allows you to set resources or disable onboard system
devices.

• System BIOS

• Chassis serial number

• Asset tracking number

• ME firmware version

• Management node

Computer Setup Menu (Continued)

Heading Option / Description

PCI Devices - Lists installed PCI devices with their IRQ settings and allows
you to reconfigure IRQ or disable devices.

PCI VGA Configuration - Allows you to specify which VGA controller will
be used when multiple video adapters are available.

Bus Options (some models) - Allows you to enable/disable PCI SERR#
Generation and PCI VGA palette snooping.

Device Options - Allows you to set:

• Printer Mode - Bi-Directional, EPP & ECP, Output Only

• Num Lock state at power-on - off/on

• S5 Wake on LAN - enable/disable

• Processor cache - enable/disable

• Integrated video - enable/disable

• Multi-Processor - enable/disable

• Internal speaker - enable/disable

• Monitor Tracking - enable/disable

• NIC PXE Option ROM Download - enable/disable

Management Devices - Only displayed in Advanced menu when BIOS
detects multiple management options.

Management Operations - Allows you to set:

• MEBx Setup Prompt - enable/disable

• Remote Help Prompt - enable/disable

• Remote Help Lockout - enable/disable

• Remote Help Connection Timeout - 5, 10, 15, 20, 30, 40, 50, 60, 120,
180, 240 seconds

• SOL Character Echo - enable/disable

• SOL Terminal Emulation Mode - enable/disable

• SOL Keyboard (enable/disable

System Hardware Interrupts

IRQ System Function IRQ System Function

0 Timer Interrupt 8 Real-Time Clock

1 Keyboard 9 Unused

2 Interrupt Controller Cascade 10 Unused, available for PCI

3 Serial Port (COM B) 11 Unused, available for PCI

4 Serial Port (COM A) 12 Mouse

5 Unused, available for PCI 13 Coprocessor

6 Diskette Drive 14 Primary ATA (IDE) Controller

7 Parallel Port (LPT 1) 15 Secondary ATA (IDE) Controller

Common POST Error Messages

Screen Message Probable Cause Recommended Action

101-Option ROM Error 1. System ROM checksum

103-System Board
Failure

164-Memory Size Error
and
201-Memory Error

214-DIMM Configura­tion Warning

301-, 304-Keyboard error Keyboard failure. Check keyboard connection or

501-Display Adapter
Failure

1720-SMART Hard Drive
Detects Imminent Failure

1796-SATA Cabling Error One or more SATA devices

1801-Microcode Patch
Error

error.

2. Expansion board option
ROM checksum

DMA, timers 1. Clear CMOS memory.

Incorrect memory configu­ration

Populated DIMM configura­tion is not optimized

Graphics display controller. 1. Reseat graphics card.

Hard drive is about to fail. 1. Determine if hard drive is

are improperly attached. For
optimal performance, the
SATA 0 and SATA 1 con­nectors must be used before
SATA 2 and SATA 3.

Processor not supported by
ROM B IOS.

1. Verify ROM, reflash if required

2. Remove suspected card, reboot

3. Clear CMOS memory, reboot

4. Replace system board

2. Remove expansion boards.

3. Replace system board.

1. Run Setup (F10).

2. Check DIMMs for proper
seating, type, and HP
compatibility.

3. R emove DIMMs singularly and
reboot to isolate faulty DIMM.

4. Replace system board.

Rearrange the DIMMs so that
each channel has the same amount
of memory.

keys. Check connector for bent of
missing pins. Replace keyboard. If
304, possible system board prob­lem.

2. Clear CMOS.

3. Check monitor connection.

4. Replace graphics card.

giving correct error message.
Enter Computer Setup and run
the Drive Protection System
test under Storage > DPS Self-
test.

2. Apply hard drive firmware
patch if applicable.

3. Back up contents and replace
hard drive.

Ensure SATA connectors are used
in ascending order. For one
device, use SATA 0. For two
devices, use SATA 0 and SATA 1.
For three devices, use SATA 0,
SATA1, and SATA 2.

1. Upgrade BIOS to proper
version.

2. Change the processor.

dc7900 Illustrated Parts & Service Map, USDT Chassis 506595-003 page 3

Failsafe Boot Block ROM

The computer comes with a reprogrammable flash system ROM (read only memory). To
upgrade the ROM, download the latest ROM BIOS image from the HP Web site (www.hp.com)
and follow the online GUI/instructions.

Your system ROM includes a Failsafe Boot Block that is protected during the flash process and
allows the computer to be restarted in the unlikely event of an unsuccessful ROM flash.

If the system detects an invalid system ROM during the boot sequence, the Failsafe Boot Block
attempts to locate a valid BIOS image on removable media. To recover from the Boot Block
recovery mode complete the following steps:

Boot Block Recovery

1. Remove any bootable media from the computer and turn off power.

2. Insert a flash drive or CD containing the ROM BIOS in the root directory. The media must be
formatted using the FAT12, FAT16, or FAT32 file system.

3. Turn on power to the system.

4. The system will automatically flash the ROM.

NOTE: BitLocker prevents Windows Vista from booting when a CD containing the BIOS image
file is in an optical drive. If BitLocker is enabled, remove this CD before attempting to boot to
Wind ows Vist a.

Password Security

Establishing a Setup or Power-On password:

1. Turn on or restart the computer. If you are in Windows, click Start > Shut Down >Restart.

2. As soon as the computer is turned on, press F10 when the monitor light turns green to enter
Computer Setup. Press Enter to bypass the title screen, if necessary. If you do not press F10
when prompted, a restart will be necessary.

3. To establish a Setup password, select Security > Setup Password and follow the instructions
on the screen.

- or ­To establish a Power-On password, select Security > Power-On Password and follow the
instructions on the screen

4. Before exiting, click File > Save Changes and Exit.

Changing a Setup or Power-On password:

1. Turn on or restart the computer. If you are in Windows, click Start > Shut Down > Restart.

To change the Setup password, go to step 2.
To change the Power-on password, go to step 3.

2. To change the Setup password, as soon as the computer is turned on, press F10 when the
monitor light turns green to enter Computer Setup. Press Enter to bypass the title screen, if
necessary.

3. When the key icon appears, type your current password, a slash (/) or alternate delimiter
character, your new password, another slash (/) or alternate delimiter character, and your new
password again as shown:

current password/new password/new password.

NOTE: Type the new password carefully since the characters do not appear on the screen.

4. Press Enter.

The new password will take effect the next time the computer is restarted.

Deleting a Power-On or Setup password

1. Turn on or restart the computer. If you are in Windows, click Start > Shut Down > Restart.

To delete the Setup password, go to step 2.
To delete the Power-On password, go to step 3.

2. To change the Setup password, as soon as the computer is turned on, press F10 when the
monitor light turns green to enter Computer Setup. Press Enter to bypass the title screen, if
necessary.

3. When the key icon appears, type your current password followed by a slash (/) or alternate
delimiter character as shown. Example: currentpassword/

4. Press Enter.

Error Conditions and Messages

Feature Purpose

Floppy drive controller Prevents the transfer of data to or from the

Device Boot Disabling Prevents booting from and or all of these

Security Option Prevents use of computer until password is

BIOS Write Protect Restricts ability to change ROM BIOS with-

USB Controller Allows you to disable or enable all USB

Diagnostic LEDs

LED Color LED Activity State/Message

Power Green On Computer on

Power Green 1 blink every 2 seconds Normal Suspend Mode

Power Red 1 blink every second followed

Power Red 3 blinks, 1 blink every second

Power Red 4 blinks, 1 blink every second

Power Red 5 blinks, 1 blink every second

Power Red 6 blinks, 1 blink every second

Power Red 7 blinks, 1 blink every second

Power Red 8 blinks, 1 blink every second

Power Red 9 blinks, 1 blink every second

Power Red 10 blinks, 1 blink every second

Power Red 11 blinks, 1 blink every second

none none System does not power on and

floppy drive.

devices: Internal or external USB, Internal
ODD, or Internal FDD

entered. Can apply to both initial startup and
restart.

out approval.

devices.

by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

followed by a 2 second pause

LEDs are not flashing

CPU thermal shutdown

Processor not installed

Power failure (power supply overload)

Pre-video memory error

Pre-video graphics error

System board failure (ROM

Invalid ROM based on Checksum

System powers on but is unable to boot

Bad option card

The current processor does not support
a feature previously enabled on this
system.

System unable to power on

How It Is
Established

Setup Utilities

Setup Utilities

Setup Utilities

Setup Utilities.

Setup Utilities

Security Features
Diagnostic Functions

Diagnostic functions are provided by the Setup Utility (in system ROM) and by HP Insight
Diagnostics. HP Insight Diagnostics provides detailed system information including:

• Processor type and speed

• Memory amount, mapping, and integrity

• Hardware peripheral availability/settings

• Hard drive type, space used/available

• System identification, asset tracking

Insight Diagnostics may be found on the Documentation and Diagnostics CD that shipped with
the computer. The tool may also be downloaded from the HP Web site using the following pro­cedure:

1. Go to www.hp.com

2. Click the Software & Download driver link.

3. Enter the product number (for example, dc7900) in the text box and press the Enter key.

4. Select the specific product.

5. Select the OS.

6. Click the Diagnostics link.

7. Select HP Insight Diagnostics Offline Edition.

8. Click Download.

NOTE: The download includes instructions on how to create a bootable CD.

Clearing CMOS

1. Turn off the computer and any external devices, and disconnect the power cord from the
power outlet.

2. Remove the chassis access panel.

3. On the system board, press and hold the CMOS button for 5 seconds.

4. Replace the chassis access panel and reconnect the power cord.

5. Turn on the computer and allow it to start.

dc7900 Illustrated Parts & Service Map, USDT Chassis 506595-003 page 4