HP dc7800 tower manual Table A-2Diagnostic Front Panel LEDs and Audible Codes

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Interpreting POST Diagnostic Front Panel LEDs and Audible Codes

This section covers the front panel LED codes as well as the audible codes that may occur before or during POST that do not necessarily have an error code or text message associated with them.

WARNING! When the computer is plugged into an AC power source, voltage is always applied to the system board. To reduce the risk of personal injury from electrical shock and/or hot surfaces, be sure to disconnect the power cord from the wall outlet and allow the internal system components to cool before touching.

NOTE: If you see flashing LEDs on a PS/2 keyboard, look for flashing LEDs on the front panel of the computer and refer to the following table to determine the front panel LED codes.

Recommended actions in the following table are listed in the order in which they should be performed.

Not all diagnostic lights and audible codes are available on all models.

Table A-2Diagnostic Front Panel LEDs and Audible Codes

Activity

Beeps

Possible Cause

Recommended Action

 

 

 

 

Green Power LED On.

None

Computer on.

None

 

 

 

 

Green Power LED flashes

None

Computer in Suspend to

None required. Press any key or move the mouse

every two seconds.

 

RAM mode (some models

to wake the computer.

 

 

only) or normal Suspend

 

 

 

 

mode.

 

 

 

 

 

 

 

Red Power LED flashes two

2

Processor thermal

1.

Ensure that the computer air vents are not

times, once every second,

 

protection activated:

 

blocked and the processor cooling fan is

followed by a two second

 

A fan may be blocked or

 

running.

pause. Beeps stop after fifth

 

 

 

iteration but LEDs continue

 

not turning.

2.

Open hood, press power button, and see if

until problem is solved.

 

OR

 

the processor fan spins. If the processor fan

 

 

 

is not spinning, make sure the fan's cable is

 

 

The heatsink/fan

 

plugged onto the system board header.

 

 

 

 

 

 

assembly is not properly

3.

If fan is plugged in, but is not spinning, then

 

 

attached to the processor.

 

replace heatsink/fan assembly.

 

 

 

4.

Contact an authorized reseller or service

 

 

 

 

provider.

 

 

 

 

 

Red Power LED flashes three

3

Processor not installed

1.

Check to see that the processor is present.

times, once every second,

 

(not an indicator of bad

2.

Reseat the processor.

followed by a two second

 

processor).

pause. Beeps stop after fifth

 

 

 

 

iteration but LEDs continue

 

 

 

 

until problem is solved.

 

 

 

 

Red Power LED flashes four

4

Power failure (power

times, once every second,

 

supply is overloaded).

followed by a two second

 

OR

pause. Beeps stop after fifth

 

iteration but LEDs continue

 

The incorrect external

until problem is solved.

 

 

 

power supply adapter is

being used on the USDT.

1.Open the hood and ensure the 4 or 6-wire power supply cable is seated into the connector on the system board.

2.Check if a device is causing the problem by removing ALL attached devices (such as hard, diskette, or optical drives, and expansion cards). Power on the system. If the system enters the POST, then power off and replace one device at a time and repeat this procedure until failure occurs. Replace the device that is causing the failure. Continue adding devices one at a time to ensure all devices are functioning properly.

ENWW

Interpreting POST Diagnostic Front Panel LEDs and Audible Codes 55

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Contents Troubleshooting Guide Troubleshooting Guide Iii Iv About This Book Table of contents Accessing DPS Through Computer Setup HP Insight Diagnostics HP Insight DiagnosticsSurvey Tab Test Tab Log Tab Select a language and click Download Protecting the SoftwareProtecting the Software HP Backup and Recovery Manager Safety and Comfort Safety and Comfort Before You Call for Technical SupportHelpful Hints Troubleshooting Without DiagnosticsHelpful Hints 1Solving General Problems Solving General ProblemsComputer date and time display is incorrect Cause Solution There is no sound or sound volume is too low Cause Solution Solving General ProblemsCannot remove computer cover or access panel Cause Solution Poor performance is experienced Cause SolutionCause unknown Restart the computer Cause SolutionEnww 2Solving Power Problems Solving Power ProblemsPower supply shuts down intermittently Cause Solution Solving Diskette Problems Solving Diskette Problems3Solving Diskette Problems Problem has occurred with a disk transaction Cause Solution Cannot format diskette Cause SolutionDiskette drive cannot read a diskette Cause Solution Invalid system disk message is displayed Cause SolutionSecurity Password Options 4Solving Hard Drive Problems Solving Hard Drive ProblemsStorage Boot Order list Solving Hard Drive ProblemsComputer will not boot from hard drive Cause Solution Device ConfigurationTroubleshooting Without Diagnostics Solving Media Card Reader Problems Solving Media Card Reader Problems5Solving Media Card Reader Problems Can not write to the media card Cause SolutionTroubleshooting Without Diagnostics Solving Display Problems Solving Display Problems6Solving Display Problems Blank screen no video Cause SolutionDim characters Cause Solution Out of Range displays on screen Cause Solution Image is not centered Cause SolutionSelect ImageControl/ Horizontal Position or Vertical Certain typed symbols do not appear correct Cause Solution Solving Audio Problems Solving Audio Problems7Solving Audio Problems Sound cuts in and out Cause SolutionLine-in jack is not functioning properly Cause Solution Sound from headphones is not clear or muffled Cause SolutionSolving Printer Problems Solving Printer Problems8Solving Printer Problems 9Solving Keyboard Problems Solving Keyboard and Mouse Problems10Solving Mouse Problems Select Shut DownSolving Keyboard and Mouse Problems 11Solving Hardware Installation Problems Solving Hardware Installation ProblemsComputer will not start Cause Solution Goes away Solving Hardware Installation ProblemsOnce bad card is identified, remove and replace bad Option card12Solving Network Problems Solving Network ProblemsWake-on-LAN feature is not functioning Cause Solution Network status link light never flashes Cause Solution Solving Network ProblemsDiagnostics reports a failure Cause Solution New network card will not boot Cause Solution Solving Memory Problems Solving Memory Problems13Solving Memory Problems Troubleshooting Without Diagnostics Solving Processor Problems Solving Processor Problems14Solving Processor Problems Some fans only operate when needed15Solving CD-ROM and DVD Problems Solving CD-ROM and DVD ProblemsMode in Security Password Options Movie will not play in the DVD drive Cause SolutionCannot eject compact disc tray-load unit Cause Solution Solving CD-ROM and DVD Problems16Solving Drive Key Problems Solving Drive Key ProblemsUSB Drive Key not found identified Cause Solution System will not boot from USB Drive Key Cause SolutionSolving Front Panel Component Problems Solving Front Panel Component Problems17Solving Front Panel Component Problems 18Solving Internet Access Problems Solving Internet Access ProblemsUnable to connect to the Internet Cause Solution Click on System and Maintenance Solving Internet Access ProblemsDouble-clickAgere Systems PCI-SV92PP Soft Modem19Solving Software Problems Solving Software ProblemsContacting Customer Support Contacting Customer SupportPost Error Messages Post Numeric Codes and Text Messages Post Numeric Codes and Text MessagesTable A-1Numeric Codes and Text Messages Control panel message Description Recommended actionContact an authorized dealer or reseller for Advanced Onboard Devices Computer Setup or Windows utilities Sata Under Storage DPS Self-testKeyboard failure while Network Server Mode Activity Beeps Possible Cause Recommended Action Table A-2Diagnostic Front Panel LEDs and Audible CodesUse the Smart ID technology before Red Power LED flashes ten Bad option card Cmos Resetting the Password Jumper Resetting the Password JumperClearing and Resetting the Cmos Figure B-1 Cmos button Locate, press, and hold the Cmos button in for five secondsDrive Protection System DPS Select Storage DPS Self-Test Accessing DPS Through Computer SetupIndex
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dc7800 tower specifications

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