20 Most Recent Dell Precision Workstation 490 - MT - 32bit Dual Core Intel Xeon Processor 5120 1.... PC Desktop Questions & Answers

This issue can be resolved by disconnecting the AC power cable from the system and draining the power from the system by pressing and holding the power button on the front of the chassis. (Approximately 30 seconds). Reconnect the AC Power cord and restart the system, issue should be resolved link http://stuartconnections.com/products/Computers/Systems/Desktops/Dell/Precision_690/Users_Guide/tools.htm#wp1056136

As description of Manual of the pc , led 4 is means The computer is in a normaloff condition; the computer isconnected to an electricaloutlethttps://www.manualslib.com/manual/36893/Dell-Precision-Dcd0.html?page=35#manual1 and 3 illuminate for Memory modules are detected, but a memory configuration or compatibility error exists.solutions• Ensure that no special memory module/memory connector placement requirements exist. • Verify that the memory modules that you are installing are compatible with your computer. • Reinstall the memory modules and restart the computer. • If the problem persists, contact Dell. (if have warranty)But you can install and check one module at a time.if not compatible each other may not display.https://www.manualslib.com/manual/36893/Dell-Precision-Dcd0.html?page=40#manual

The 2nd link here should be helpful
http://www.fixya.com/support/r4282412-find_no_post_diagnostic_information_dell
Generally, this is a RAM issue

I would recommend a 500Watt power supply, they are around 30 pounds and can be bought from any PC supplier.

you can get a usb wifi device which is available in market

Most likely cause is the power supply, if it really wont turn on, if it comes on but doesnt start, the you have a computer problem. Check and see if the fans work when you push the power button or if any lites come on, then the power supply is most likely OK. If the computor does actually come on, but does not start, see how may beeps it makes. then repost your question with that info.

Corrupted O/S or damaged Hard disc. Electro help

try to clean the memory slot of your computer as well as the memory module then power up your PC. just do hardware maintenance by means of cleaning all any dust inside the computer. Hope it helps thanks.

Either the power supply has failed or the power cable is not getting power to the board (if the lights are amber). Check that the power cable from the power supply to the motherboard is fully seated. You may need to replace the power supply - you will need one that will fit your case and matches the various devices and plugs that you currently have. (20+4 pin for the motherboard gives the most flexibility, additional power for the CPU (4 pin or 8 pin), SATA if you have SATA devices, regular 4 pin peripherals for IDE hard drives and optical drives, 4 pin floppy, video card (if you have a PCIe card that needs a 6 pin plug), etc.)

I hope this helps.

Cindy Wells

You have to give me more information than that

Use the twist motion, twist the heatsink back and forth on the horizontal plane gently. This will allow air to move between the two flat surfaces.Therefore reducing suction.Take care!damnor01

I normally post this link:
http://www.fixya.com/support/r4282412-find_no_post_diagnostic_information_dell
but I think I can get better info for you here:
http://support.dell.com/support/edocs/systems/ws490/en/ug/tools.htm#wp1057769
2 things.
The power led flashing amber can mean a failure of one rail in the power supply, or a bad connection (The cables are removable from the power supply) so you may try reseating power connections internally.
1 & 3 LEDs can mean a RAM failure

Hi:
Having the 1,2,3 lights on means that the computer is booting up well, but waiting on the video to initialize. You should open the case and make sure that the video card is properly seated in its socket.If it is, then it would still be the most likely suspect to cause your problem.

You can use the Upgrade option during Windows 7 installation, which preserves your files, settings, and programs, only if you're currently running a 32-bit version of Windows Vista and you want to upgrade to the 32-bit version of Windows 7. Similarly, if you are running a 64-bit version of Windows Vista, you can only perform an upgrade to a 64-bit version of Windows 7. For more information, go to Upgrading to Windows 7: frequently asked questions on the Windows website.
If you want to move from a 32-bit version of Windows to a 64-bit version of Windows 7 or vice versa, you'll need to back up your files and choose the Custom option during Windows 7 installation. Then, you'll need to restore your files and reinstall your programs. For more information about performing a custom installation, see Installing and reinstalling Windows 7‍.
Notes

• To install a 64-bit version of Windows 7 on a computer running a 32-bit version of Windows, you'll need to start, or boot, your computer using a 64-bit Windows 7 installation disc or files.
  
• If you start your computer using a 64-bit Windows 7 installation disc or files, but your computer isn't capable of running a 64-bit version of Windows, you'll see a Windows Boot Manager error. You'll need to use a 32-bit Windows 7 installation disc or files instead.
  
• Windows Easy Transfer can't transfer files from a 64-bit version of Windows to a 32-bit version of Windows. If you're running a 64-bit version of Windows Vista but you plan to install a 32-bit version of Windows 7, you can move your files to an external location manually or use Backup and Restore in Windows Vista. For more information, go to Back up your files and
  

If you are getting no video at all, then we can use the diagnostic LEDs and the power LED to help determine the failure.
http://www.fixya.com/support/r4282412-find_no_post_diagnostic_information_dell

CPU is overheating - the heatsink may be loose or no thermal paste.
Take heatsink off and have a look.
Go into BIOS and view hardware readings - watch CPU temp to see if it risees.