Checked with my geek husband - he tells me that repairing an old Tablet really isn't worth it, assuming you could get it repaired at all. It's very easy to get new ones now - when you bought yours they had only just come out and now they're everywhere. Also, you're in New York and you'd probably get it cheaper there than in Germany, and of course it would be a far, far better spec. For example, an excellent HP Tablet with five-star reviews is $1050 at Best Buy - convert that into €!), and there are cheaper models too.
If you're not in a position to buy online (check slickdeals.net) for any current special offers, talk to people in shops like Best Buy. He also recommends looking at Ultraportable laptops - very light, very thin (more so than Tablets), just not with a touch-sensitive screen.
Good luck!
Wendy