Although that is normally associated with a memory issue, I'm going to take you through a few steps here just to be sure
1) Remove the memory modules and then put them back in
2) With battery out and power adapter unplugged, press and hold the power button for ~30 seconds
Hopefully that'll get you up and running.
One possibility that affects Dell machines in particular is if the CMOS battery has gone bad, that can cause all kinds of funky behavior. If doing the two steps above do not help, I'll suggest replacing the CMOS battery (little button-type battery on the motherboard)