China.
Here's the USA based contact for these products:
http://estone-tech.com/5.html
Honestly, it appears to be a double-DIN (or close) receiver and no one repairs this sort of stuff anymore... If they won't repair/replace - an exact replacement will cost you $100-$250 on ebay (current). However, I'd probably put a modern head unit in there that will do the same thing - from a real company with some history / support /warranty.
History says they've sold cheap - $25-$75 on ebay before, but you'll have to watch for one.
Or new, through crutchfield, which will support/warranty it:
http://www.crutchfield.com/S-Gr4z2jl...iRV6500BT.html ($299)