If the output of the older chargers seems to match the output of the current one, but the plug is a bit larger, you could try one of these:
http://www.amazon.com/Nokia-Charger-...dp/B0009RFX24/

The N800 also charges, tho slowly, from the usb port:
http://www.amazon.com/Nokia-276959-U...dp/B000QGF8OQ/

I bought a new charger but the tablet is not charging. I plugged it in and left it a while and tried to turn the tablet on and it came on just to light up the Nokia screen for a couple second and went off. I thought I'd leave it plugged in all night and try turning it on. Same results.. It never stays on long enough to actually turn the system on or to see if it is charging. I get those same results with the old original charger.
I could be wrong but I am thinking it is not the charger that is the problem.
Thought or suggestions?

well it could be the charging circuit inside the tablet, or it could rhaps be the battery (but i would have thought then it would power on at all).

i do wonder if nokia has a external battery charger so that you could pop the battery out and try to charge it that way. hard to tell if it would be worth the effort tho.

from your earlier post where you stated that the unit fell with the cord plugged in my guess would be the coaxial socket on the n800.
I have fixed laptops with the same problem by soldering wires to the charge input pionts and tieing a knot in the wire to keep it from pulling out through charging port. then attach a female in-line coaxial plug and replace the tip on your charging cord with one that fits the plug.

not elegant but functional.

I have never soldered anything and don't have a soldering iron. Also I have never tried too open the inside beyond the battery or SD card slots. Don't know how to. Guess I could maybe find someone who can do it for me if that is the problem or search for a video maybe.

tso -That is a good idea to charge externally. Never thought about that. Shame it is not the same battery as one of my digital cameras and I could try charging the battery in their chargers. I don't think the battery is bad because the tablet worked after dropping it until the battery went dead.

Frustrating because I love my N800.Thanks for the suggestions!

I guess charging the battery in a different Nokia device that take the same kind could also work. I know a relative of mine operated a phone that way for a number of years.

Looks like this might be compatable. I think I will give it a try.
http://www.tmart.com/NB5L-Battery-Ch...paign=product/

looks to me like it charges canon nb-5l camera batteries, not bp-5l nokia phone batteries.

Thanks tso. I have searched Google looking at chargers and it gets a bit confusing.
There are a few universal chargers that claim to charge any Li-Ion phone or camera battery. Probably junk.
This link says it is for BP 5L but for Canon and no mention of Nokia.
http://www.amazon.com/Equivalent-Ext.../dp/B001GII4JE

Not sure why the product title says BP-5L, as the details clearly state NB-5L. Sorry.