7 Plutonium

Re: Optiplex 755 only turns on through power supply button, no video output.

Contents: Dell Optiplex 755 - Documentation

Which Model?

Dell™ OptiPlex™ 755 User's Guide

 

 Mini Tower Computer <ADMIN NOTE: Broken link has been removed from this post by Dell>

 Desktop Computer <ADMIN NOTE: Broken link has been removed from this post by Dell>

 Small Form Factor Computer <ADMIN NOTE: Broken link has been removed from this post by Dell>

 Ultra Small Form Factor Computer <ADMIN NOTE: Broken link has been removed from this post by Dell>

Diagnostic Lights

 CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.

To help troubleshoot a problem, your computer has four lights labeled 1, 2, 3, and 4 on the front panel. When the computer starts normally, the lights flash before turning off. If the computer malfunctions, the sequence of the lights help to identify the problem.

 NOTE: After the computer completes POST, all four lights turn off before booting to the operating system.

Light Pattern 

Problem Description

Suggested Resolution

The computer is in a normal off condition or a possible pre-BIOS failure has occurred.

The diagnostic lights are not lit after the computer successfully boots to the operating system.

  • Plug the computer into a working electrical outlet (see Power Problems). <ADMIN NOTE: Broken link has been removed from this post by Dell>
  • If the problem persists, contact Dell (see Contacting Dell).

A possible processor failure has occurred.

  • Reseat the processor (see Processor information for your computer).
  • If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ).

Memory modules are detected, but a memory failure has occurred.

  • If two or more memory modules are installed, remove the modules (see Removing Memory), then reinstall one module (see Installing Memory) and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error.
  • If available, install working memory of the same type into your computer (see Installing Memory).
  • If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ).

A possible graphics card failure has occurred.

  • Reseat any installed graphics cards (see the "Cards" section for your computer).
  • If available, install a working graphics card into your computer.
  • If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ).

A possible floppy drive or hard drive failure has occurred.

Reseat all power and data cables.

A possible USB failure has occurred.

Reinstall all USB devices and check all cable connections.

No memory modules are detected.

  • If two or more memory modules are installed, remove the modules (see Removing Memory), then reinstall one module (see Installing Memory) and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error.
  • If available, install working memory of the same type into your computer (see Installing Memory).
  • If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ).

Memory modules are detected, but a memory configuration or compatibility error has occurred.

  • Ensure that no special requirements for memory module/connector placement exist (see Memory).
  • Ensure that the memory you are using is supported by your computer (see the "Specifications" section for your computer).
  • If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ).

A possible expansion card failure has occurred.

  1. Determine if a conflict exists by removing an expansion card (not a graphics card) and restarting the computer (see the "Cards" section for your computer).
  2. If the problem persists, reinstall the card you removed, then remove a different card and restart the computer.
  3. Repeat this process for each expansion card installed. If the computer starts normally, troubleshoot the last card removed from the computer for resource conflicts (see Troubleshooting Software and Hardware Problems in the Microsoft® Windows® XP and Microsoft Windows Vista® Operating Systems). <ADMIN NOTE: Broken link has been removed from this post by Dell>
  4. If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ).

Another failure has occurred.

  • Ensure that all hard drive and optical drive cables are properly connected to the system board (see the "System Board Components" section for your computer).
  • If there is an error message on the screen identifying a problem with a device (such as the floppy drive or hard drive), check the device to make sure it is functioning properly.
  • If the operating system is attempting to boot from a device (such as the floppy drive or optical drive), check system setup (see System Setup) to ensure the boot sequence is correct for the devices installed on your computer.
  • If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ).


Beep Codes

Your computer might emit a series of beeps during start-up if the monitor cannot display errors or problems. This series of beeps, called a beep code, identifies a problem. For example, beep code 1-3-1 (one possible beep code) consists of one beep, a burst of three beeps, and then one beep. This beep code tells you that the computer encountered a memory problem.

Reseating the memory modules may correct the following beep code errors. If the problem persists, contact Dell (see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> ) for instructions on obtaining technical assistance.

Code

Cause

1-3-1 through 2-4-4

Memory not being properly identified or used

4-3-1

Memory failure above address 0FFFFh

If you experience any of the following beep code errors, see Contacting Dell <ADMIN NOTE: Broken link has been removed from this post by Dell> for instructions on obtaining technical assistance.

Code

Cause

1-1-2

Microprocessor register failure

1-1-3

NVRAM read/write failure

1-1-4

ROM BIOS checksum failure

1-2-1

Programmable interval timer failure

1-2-2

DMA initialization failure

1-2-3

DMA page register read/write failure

1-3

Video Memory Test failure

1-3-1 through 2-4-4

Memory not being properly identified or used

3-1-1

Slave DMA register failure

3-1-2

Master DMA register failure

3-1-3

Master interrupt mask register failure

3-1-4

Slave interrupt mask register failure

3-2-2

Interrupt vector loading failure

3-2-4

Keyboard Controller Test failure

3-3-1

NVRAM power loss

3-3-2

Invalid NVRAM configuration

3-3-4

Video Memory Test failure

3-4-1

Screen initialization failure

3-4-2

Screen retrace failure

3-4-3

Search for video ROM failure

4-2-1

No timer tick

4-2-2

Shutdown failure

4-2-3

Gate A20 failure

4-2-4

Unexpected interrupt in protected mode

4-3-1

Memory failure above address 0FFFFh

4-3-3

Timer-chip counter 2 failure

4-3-4

Time-of-day clock stopped

4-4-1

Serial or parallel port test failure

4-4-2

Failure to decompress code to shadowed memory

4-4-3

Math-coprocessor test failure

4-4-4

Cache test failure


Report Unresolved Customer Service Issues
here

I do not work for Dell. I too am a user.

The forum is primarily user to user, with Dell employees moderating
Contact USA Technical Support






Get Support on Twitter @DellCaresPro