Illustrated Parts & Service Map: HP Compaq dc7900 Ultra Slim Desktop Business PC
dc7900 Illustrated Parts & Service Map, USDT Chassis 506595-003 page 4
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
Windows Vista.
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.
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 pro-
cedure:
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.
Error Conditions and Messages
Feature Purpose
How It Is
Established
Floppy drive controller Prevents the transfer of data to or from the
floppy drive.
Setup Utilities
Device Boot Disabling Prevents booting from and or all of these
devices: Internal or external USB, Internal
ODD, or Internal FDD
Setup Utilities
Security Option Prevents use of computer until password is
entered. Can apply to both initial startup and
restart.
Setup Utilities
BIOS Write Protect Restricts ability to change ROM BIOS with-
out approval.
Setup Utilities.
USB Controller Allows you to disable or enable all USB
devices.
Setup Utilities
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
by a 2 second pause
CPU thermal shutdown
Power Red 3 blinks, 1 blink every second
followed by a 2 second pause
Processor not installed
Power Red 4 blinks, 1 blink every second
followed by a 2 second pause
Power failure (power supply overload)
Power Red 5 blinks, 1 blink every second
followed by a 2 second pause
Pre-video memory error
Power Red 6 blinks, 1 blink every second
followed by a 2 second pause
Pre-video graphics error
Power Red 7 blinks, 1 blink every second
followed by a 2 second pause
System board failure (ROM
Power Red 8 blinks, 1 blink every second
followed by a 2 second pause
Invalid ROM based on Checksum
Power Red 9 blinks, 1 blink every second
followed by a 2 second pause
System powers on but is unable to boot
Power Red 10 blinks, 1 blink every second
followed by a 2 second pause
Bad option card
Power Red 11 blinks, 1 blink every second
followed by a 2 second pause
The current processor does not support
a feature previously enabled on this
system.
none none System does not power on and
LEDs are not flashing
System unable to power on