Tomtom go 730:no maps found...

plug into a comp that is online and go to tomtom site to find out

If there was previously a map(s), and now you're getting the No Maps Found (message), it's likely that your map (data) got corrupted. You can recover by restoring your back-up copy of the map (that you'd previously done via TomTom HOME on your computer).
If you don't have a back-up copy, try using your computer's disk check utility to fix the file system (of the storage media on your GPS device). Just connect the GPS to your computer, no need to use TomTom HOME, just use the Properties tab and use the Tools to run a disk check (assuming you're using Windows).
If that doesn't work, you may want to purchase & download and install the latest copy of the map from the TomTom website (via HOME).

Read on TomTom website how to get the latest map https://www.tomtom.com/latestmap/

I had the same problem before on a TomTom GO 730. The free internal memory was too small to hold the updated map so installation failed (the download to PC was OK, the message is misleading).
It's a TomTom software bug to not check on the available free memory properly before the update process is started.
My TomTom device required a new software install from scratch. Remove any excess MP3 or unused voices before you retry the update.

No Maps Found usually means the Application on your internal memory is not the latest one, or the map did not download correctly.
Make sure when you select internal memory when updating your device on home, that you update the application as well.
V8351 should be the latest application for your device.

you can buy USA maps for any tomtom via the tomtom website

try to check the firmware update of your gps and if it is outdated download the new firmware update.

I’m happy to assist further over the phone at https://www.6ya.com/expert/ramy_d9e7ebea3891f482

you need to uninstall tomtom home and then reinstall again you can do this at
http://tomtom.com/plus/service.php?=17

this will take you to thevery latest tomtom home downoad

The 730, unlike the 930, doesn't come with European maps preloaded. You can find the most up to date Tele Atlas maps of the UK & Europe over at TomTom's Map Store.

I have managed to solve the problem of loading a new map on my Go700 using a Mac. I discovered that Tomtom is incompatible with the Leopad operaying system, despite the protestations of the idiots at Tomtom ,so I reverted to an older Mac using Tiger.
Taking the instructions given to crinold, I tried to erase the disc on the 700 using home 1.5 - and it didn't work. So I went to disc utilities, highlighted and erased the Tomtom disc, and opened home 2,5. After being refused entry several times, like being told to load an already loaded device, I persevered, and managed, slowly, to add the map I had bought for 78 euros. T]One point oif interes is that when I bought the map, they site stated it would cost 63 pounds sterling, but switched it to euros when the invoice arrived. at a rate very favourable to Tomtom - funny, that.
This is sharp practice,probably illegal in many countries,, but, to be honest, dealing with the mysterious Tomtom company is so frustrating, that I don't have the time or inclination to fight them for the money they cheated from me.
How they survive with such an awful product and extremely bad after sales service is hard to understand - perhaps they won't ... we live in hope.