bobracing wrote:downloading them now and try

I've just done a lot of reading up on your device and many people have tried different navcores without success...some will start up but either the menus or the sounds don't work which is of no use. A word of warning - if you keep trying different navcores there is the very real possibility you could end up bricking it as others have done in the past.
There are a handful of problematic TT devices and I'm afraid yours is one of them. Personally I would either try your other solution with a paid map or give up and buy a more modern Go 520 which can be bought quite cheaply on eBay and has free maps
Good luck in whatever you decide to do