|You are supposed to unplug the AC adapter from the laptop, AND remove it's main battery, BEFORE, and while, you remove or install ram. |
Did you do BOTH ?
If you didn't remove both, you may have damaged the ram, and/or the ram slot circuits.
The ATX mboard is always powered in some places, including some of the contacts in the ram slots, even when the computer is not running, as long as at least the main battery is installed.
If you did remove both, the ram may not be seated properly.
Remove both the AC adapter connection and the main battery, remove the ram, and install it again.
The notch on the contact edge of the modules MUST line up with the bump in the slot, and the ram modules must be all the way into their slots, and be "latched" so they can't move by clips or whatever retains them.
It's a good idea to wipe off the contacts on the modules with a tissue or soft cloth.
Don't touch the contacts with your fingers.
If in doubt, READ the Dell Owner's or Service manual for your model, for how to properly remove and install the modules.
E.g. search for: Dell Inspiron 6000 manuals
on the the web
Lots of the first "hits" will be on the Dell site.
If you installed either module backwards, when you restore power to the laptop, when you attempt to boot the computer, that ram module that is backwards and the ram slot it is in are both fried instantly - you will have noticed a strong smell like that of burnt plastic, if your sense of smell is any good.
By the way, most more recent laptops will not boot at all, or will not boot fully, if the AC adapter is connected but the main battery is not installed.