Video shuts off, keyboard lights go off, fan speeds up to very high - General Hardware - Desktop - Dell Community

Video shuts off, keyboard lights go off, fan speeds up to very high


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Video shuts off, keyboard lights go off, fan speeds up to very high

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This is about a Dell� OptiPlex� GX280



A variable time after Windows XP-32 pro boot, generally when going to more graphic intense display, the screen goes blank and then the monitor displays its message that there is no video and it will go into power save mode.  Meanwhile, the keyboard num-lock led goes dark.  Many times, if the problem occurs when displaying graphics on a web site, or a video, the CPU fan goes to very high speed.  The desktop power LED is green.  Holding the power button in for 30 seconds or longer does not shut down the fan or the LED. 

Only unplugging the computer gets control.  Then, the power button has to be touched to start what appears to be a normal POST boot.  There is no difference if I try this right away or after the power has been unplugged for hours.  No boot error messages or diagnostics LEDs (this is small desktop cabinent).  For a while today, the issue shut down the computer as soon as the screen tried to display the initial Windows boot screen.  I tried booting in safe mode, with the command prompt and VGA options, but the crash would occurs as soon as the pause for the Win boot screen (though the fan remained silent in these situations).  I tried rolling back the configuration several times, and this may have helped, as I started being able to get to the Windows screen, enter my password and get a normal desktop.  One time I was able to start a program and the crash occurred.  Most other times the crash occurred at some point before the system finished fully booting. 

When the problem first started, it was associated with display of a video on a web site.  However, within two days it now prevents fully booting.

Because the video dying is the first symptom, I am wondering about the integrated video.  I changed the BIOS setting from using 8 MB of memory to only using 1 MB for video, in case writing to a particular memory location was triggering a short.  This did not appear to make a difference in the next boot.  I remain suspicous of a memory problem because it acts a bit like a short is stressing the CPU (fan goes to full speed), and LEDs appear to freeze in what ever state they were in (if the HD light was on at the occurance - it stays on until the power plug is pullted; if the HD was off, it never blinks on either).

So I wonder whether to buy a video board, or try removing some of the memory (it is configured with two 512 GB DIMMs and two 256 GB DIMMS, for a listed 1.5 GB in the BIOS display. 

Anyone seen a similar set of symptoms?


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  • I have a Vostro 410 Desktop and have experienced almost identical problem. Thanks to your post, unplugging has solved the issue. The problem was intermittent with  no logical reason. This latest time happened after the power/phone leads were tripped over. Connections were checked and appeared  to be OK. Maybe your thought about a short is logical and bumping the leads may have caused a quick temporary short. Who knows, but thanks for your input.


  • Unfortunately, in my case, the shutdown does not have any mechanical or thermal trigger.  I can try re-powering right away and the boot process always gets through POST.  The time to shut down is variable, but this morning it almost looked like I was going to be able to copy a quicken database to an external drive before it shutdown.  Further observations this morning is that all of the rear panel LED indicators are on, the RJ-45 continues to blink.  However, the router says the node is inactive.  I opened it up and probed the voltage connector to the main board.  Voltages looked good, but I did not find a negative supply pin, either while the computer was working and after it shutdown.  Is a negative voltage still used?

  • Further update:  I found the pinout chart for the 20 pin connector to the mother board and all of the voltages are as they should be, both when the computer is operating and after it has died.  Same for the 12 supplies to the P4.  I have removed one pair of DIMMs, then the other, without any impact on the problem.  I have cleaned the CPU cooler fins and checked the operation of the fan.  All looks good.  Yet the problem remains, random shutdowns if booting gets as far as Windows or right at the transition to Windows.  Today I left the computer in the BIOS gives the choice of different startup paths, and it was dead when I came home. So it is not conclusive that the problem is associated with the demands of the graphics.  I don't have another SATA boot drive, and putting an old Win2K IDE drive in for booting I just lost the jumper pin.  

    Got a year from this computer after buying it cheap on Ebay, so I guess I got what I paid for.