Dell Dimension 4700 boots to splash screen then screen goes blank. Diagnostic lights are all green. HD light flashes green once and then goes dark. Tried re-seating memory and all cables. Replaced motherboard battery. still no good. Any ideas? I'm running XP Pro if that helps.

Remove ALL media from the machine DVD, CD, USB, etc. Check/reseat all Monitor cables. Reboot. If that fails, unplug , plug back in in 30 seconds or so. reboot, if you get a Dell Logo, Open the boot Menu and select Boot from HDD first.

This could be caused by several faults. See the link below, the scroll down the "Advanced Troubleshooting" section, then click on the "Power lights" or Diagnostic Lights" to help you start looking for the problem. You may want to download and print out some of this information using another PC.

http://search.aol.com/aol/search?enabled_terms=&s_it=comsearch50&q=Dell+Dimension+4700+Specs

You may have an operating system problem as well. You can change the boot sequence of your PC by pressing F2 early in the bootup and using the original or restore CD/DVD, you can find out out if the hard drive has issues or if you need to reinstall Windows. Hopefully, you have a backup of your files. Reinstalling Windows can result in data loss.

Flashing Amber power LED indicates a bad power supply.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817822008&cm_re=atx_power_supply-_-17-822-008-_-Product

If the LED Is SOLID amber, it is likely either a component connected to the Motherboard or a bad motherboard

You have a rootkit virus, the only answer is reformat the drive and start fresh, sorry.
After a fresh install is done immediately install service(can be downloaded free from microsoft.com) pack 3, because sp2 is vulnerable to a host of trouble.

u may need a new hd try other hd see what hapen good luck

If you have a Dell, then do this the next time.

As soon as you see your system creating problems again, turn to the back of the computer. There are 4 LED lights. See the status of those lights, I mean, green, orange etc. Check it on support.dell.com and see if you find something useful.

Sounds like the BIOS upgrade didn't take. Those beep codes are audible indicators that the motherboard has failed POST (Power On Self Test).

Here's is a list of the codes for your specific BIOS/PC:

http://support.dell.com/support/edocs/systems/dim4700/sm/adtshoot.htm#wp1052968

i would have to disagree with jerry, while that seems reasonable if the motherboard fan isn't running at all then whether or not the video card is ok is somewhat irrelevant.
I would agree somewhat though, i think the PSU might be a good thing to check to see if it is functional.
when you power it on does the CPU fan start or shudder at least ? that would be my first guess for a problem if you had been having any problems recently

Check the BIOS and make sure it's doesn't still have to old HD in there. Are you seeing anything on the screen?

Hit F12 to get into system setup and find out what HD options you have.

plz try by resiting the ram