6 Beeps on Startup - No Monitor Display - Dimension 8400

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6 Beeps on Startup - No Monitor Display - Dimension 8400

  • PC working fine yesterday, today it won't turn on.
     
    All i get is 6 beeps on startup and no screen display.
     
    On the back panel, the A and B lights are orange and C and D green.
     
    This indicates RAM failure, however, reseating both RAM chips hasn't done anything.
     
    Have tested the monitor, it works 100%.
     
    Dimension 8400
     
    Anyone have any ideas?

    Message Edited by Doombreed on 01-05-200710:57 PM

  • Please reference this Dell document:
     
  • Doombreed
     
    Try reseating the video card. Remove the memory modules, then reinstall one module and restart the computer. If the computer starts normally, reinstall the additional module.

    If the system still will not boot, then try installing the memory in different slots. Still not working, then it's either faulty memory or a bad motherboard.

    Bev.
     
     
     
     
    Please don't send me questions about your system by DCF Messenger.
    Post the issue in the appropriate Board, where they will be answered.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Thanks guys, will try this now
  • 4 RAM slots
     
    2 RAM modules
     
    swapped them all around using every combo, nada.
     
    As for the graphics card, its an ATI Radeon XT800
     
    Very securely bolted in place.
     
    Is it worth unscrewing all the screws? I can't imagine that it would have moved
  • My Motherboard appears to be working, lights on and such.
     
    Video card is spinning, doesn't appear fried.
     
    Leads me to think the problem is with the RAM.
     
    This leads to 2 questions
     
    1) Why am i not getting a monitor display?
     
    2) What are the odds of both RAM modules dying at once?
  • The 8400 uses DDR2 RAM
     
    This means that there should be different colored tabs on the memory slot retainers.
     
    There should be an empty slot between the first stick (nearest the CPU) and the second stick. The tab ears (color) of the installed memory should match.
     
    If in the event the same problem exists with memory in the proper place
    Remove the stick farthest away from the CPU and reboot.
    If no problem the stick you removed is bad.
    If same problem, replace the memory stick nearest the CPU with the one removed and try again.
    If no problem the stick of memory outside of the computer is bad.
    If same problem, both sticks need to be tested. This does not mean they are both bad.
     
    Screw?
    I don't think the 8400 uses screws to retain any of the peripheral cards. I believe there is a green colored guillotine that holds them in place.
     
     
     
  • About status lights and whirling fans:
     
    On the 8400 motherboard there is a green reserve power LED lamp mounted to the motherboard inside the computer. When the motherboard capacitors are completely discharged, the LED will cease to glow.
     
    The 8400 has four status lamps on the back plane of the motherboard, numbered one through four, visible when the case is closed and powered on. These status lights glow in green or amber depending on status. There are two more status lights on the front bezel. One is beneath the power button which glows green when powered up, amber when asleep. The second front bezel status light is to indicate hard drive activity. The floppy, and optical drives also have activity lights.
     
    There are two key fans on a standard Dimension 8400. The first is the power supply fan and the second is the CPU fan mounted to the back plane of the computer chassis. Both of these should spin freely and quietly whenever the computer is powered up.
     
    Lastly is the video adapter card cooling fan. Not all Dimension 8400 models were shipped like this. Most came with a passive (large heat sink) cooling system to reduce noise levels. Video adapters with cooling fans were normally high end video cards or are after-market non Dell adapter.
     
    In the case of a whirling fan on a video card adapter, this does not mean it is working fine. It only indicates that the fan on the adapter has power. The adapter card still may be misaligned in the PCI-e slot. It is not at all uncommon for the steel bracket which is inserted into the chassis backplane to become misaligned with the chassis causing the adapter card to look fully seated when in reality it is not. Viewing the installed adapter card from the wide surface along the pin edge of the card should indicate a uniform line along the entire row of pins when compared to the adapter slot. If the card appears slightly higher nearest the backplane or at the rear it is misaligned. It still might work for a short time but cease when the limited contact surface is disturbed.