Downloading Free Maps for TomTom GO 720

register the device, tomtom home will reinstall the original map that was on the unit when new

One XL? One moment Il get it for you.

You may be able to get "free" map updates from (illegal) underground sources. But that's not recommended.
Yes, you're right, you can simply get a new TomTom GPS and get the latest map(s) for it. Consider getting a TomTom with lifetime maps ....and you won't have to pay for any map updates.

New maps and free software upgrades through TomTom HOME. So you’ll never be out-of-date.

Download TomTom Home:
(Click here)
http://www.tomtom.com/services/service.php?id=16&tab=87

The TomTom 520 and 720 are the same unit. the differance is the maps. The 520 has maps of the US and the 720 has maps of Europe. Download the free clearflash utility from TomTom and run it a couple of times. This should clear up your problem. Sometimes the mapset config in the map gets full and it has to be cleared.

If you download the maps using tomtom home then you should be able to revert back, or you could download the america map to a memory card

No maps found issue:
http://www.tomtom.com/support/index.php?Language=1&query=no+maps+found&FID=9838

Your best bet is to reinstall the maps, from scratch. This will ensure that all the maps are included.
This guide should help you out:
http://www.tomtom.com/support/solution.php?GID=1&PID=1682&CID=224-225&Language=1

These error's occur when units have cracked maps put on them.
When you update your tomtom device it will replace the cracked file with the original tomtom file.

these units on ebay are mainly refurbished units even tho they are in 'sealed' packaging, they opened your box, put cracked maps and sell the device for more then what they have paid for it.

Best to take it back to person you purchased it from.

avoid tomtom products from ebay, most of them have cracked maps.

Thanks,
Pabs

"Can I get maps from elsewhere..."

No, you can't...