Take a look at this page for the proper jumper configurations:
Now, after the jumpers are properly set, you'll need to go into system setup and configure your drives and other options. If after you've got everything configured, your system still won't boot, then it's time to run the Dell diagnostics and figure out what's wrong with your system.
If the jumper plug on the Clear CMOS (RTCRST) Jumper pins is in normal operating mode (pins 2 & 3) the power button does not work. I get nothing. I know power is getting to the mother board, because the green led (auxiliary power led) lights up.
If I remove the jumper entirely or set the jumper plug over pins 1 & 2 the system goes through it's power up process and the power button works but, of course, the system will not boot. I just get the cursor blinking in the upper left corner of the monitior - which was my original problem.
This is coming at the end of some trouble I've been having with the system since I put an old game (Civilization III) on it. The system would power down fine, but wouldn't boot - I'd get the blinking cursor in the upper left hand corner. Nothing I tried would fix the problem so in desperation I cleared the CMOS. It worked but the problem is back, worse than ever. I don't see how the game can be causing this, but the problem arose a few days after it was installed and the first question I always ask is - what's changed. That's the only thing I know of thats changed. My Norton Internet Security is up to date and always on. Up until the game install the system was running fine.
DELL XPS 400
Windows XP SP3
PS. I've tried joining the DELL forums, but evidently they don't like me.