Diagnostic 1 ,4 and battery lights are stable

SOURCE: Dell optiplex won't Boot-up.. Orange light on motherboard

its going to rather your power supply or your motherboard has died, id try a different power supply first

SOURCE: Dell Optiplex GX520 message:

Hey,

there is a 3 volt flat battery inside the computer, it in most cases clearly visible.


Replace it with the same type of battery, then adjust the clock in the system setup.

All done, all fine.


Let me know if you need anything else.

Thanks,
Ekse

SOURCE: Dell OptiPlex GX520 PC Desktop Problem

Hello everyone, check your cpu - I've just had one of these in for repair and the cpu was faulty - removing the ATX 4way 12v lead let the pc start rather then detecting a short and shutting the psu down. Changing the cpu cured the fault.

Thanks

Ben Wabnick

• 2404 Answers
• Posted on Jun 17, 2009

SOURCE: dell optiplex gx520 keyboard

If your dell machine is recognizing the keyboard properly and installing its own built in drivers properly then the USB ports are working and it a problem with your keyboard

SOURCE: My Dell Optiplex GX520 will not boot. There is no

If 1 & 2 are off ... then you have problems.

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

• If you have one memory module installed, reinstall it and restart the computer. (see Memory for instructions on how to remove and install memory modules.)
• If you have two or more memory modules installed, remove the modules, reinstall one module, and then restart the computer. If the computer starts normally, reinstall an additional module. Continue until you have identified a faulty module or reinstalled all modules without error.
• If available, install properly working memory of the same type into your computer.
• If the problem persists, contact Dell (see Contacting Dell).

• If you have one memory module installed, reinstall it and restart the computer. (see Memory for instructions on how to remove and install memory modules.)
• If you have two or more memory modules installed, remove the modules, reinstall one module, and then restart the computer. If the computer starts normally, reinstall an additional module. Continue until you have identified a faulty module or reinstalled all modules without error.
• If available, install properly working memory of the same type into your computer.
• If the problem persists, contact Dell (see Contacting Dell).