Dell Latitude D630 reboot problem after upgrading RAM

You probably didn't put back something correctly when you disassembled your laptop to get to the slot under the keyboard.

My guess is you have incompatible RAM. Also make sure when you put back the old RAM that you are seating it properly into the slot. If the RAM is not seated correctly into the slot it will not work. For compatible RAM I would suggest you buy from crucial.com 

I've tried reseating the old RAM chips very carefully a few times.  I've even tried switching the 2 original RAM chips, one in the MB the other in the back, but it still won't boot.  Will the laptop boot with only one of the 2 chips?  Maybe one chip is bad now, as one of them sat out on my desk for a few months.  I'd put in the 2GB ram in the back slot, but it made no difference.  A tech friend said Win would look to the MB RAM slot first and to move it there - when I did, I could never get it to boot again.

Were you properly grounded with an ESD strap?

It is always possible that improper handling zapped your old RAM chips.

Unplug the a/c adapter. Remove the hard drive, dvdrom drive, battery and RAM. Hold the power button for 30 seconds. Insert one module and power with the a/c adapter only. Hold down the power button for 30 seconds when booting up with only the a/c adapter.. See if it will boot. If it will not then try one RAM stick at a time one slot at a time. If it still will not boot you either have faulty RAM or faulty slot.. Make sure the a/c adapter is connected properly and has a power light on the brick on. Make sure the light stays on when you plug it into the computer.

Thanks for this procedure, DallasCBWC.  I've never removed the HD or the dvdrom drive but I guess I can figure out how to do this on youtube.  

Do you know if it matters which slot the RAM chips are tested in, if only one is used?  I've heard that the slot on the MB is primary, so I should use that slot if only one chip is used - is this true?   The rear slot is easier.

If this doesn't work, and assuming I can get the HD out undamaged, do you know if it would be compatible with my very old Inspiron 6000 laptop?  If yes, then I could swap out the HD and at least get my data off the Latitude's HD.  Finally, when swaping out HDs, I presume the operating system stays intact?

How will it reboot w/o the hard drive installed?  Or did you mean to reinstall either the HD or DVD with a windows disk and then try to reboot?