I'm assuming you tried to flash a new ROM on it, and something now doesn't work? It would be best to say which ROM you have tried, and also what has gone wrong. Does it boot up but no WiFi or touchscreen? Does it get stuck on the loading screen? Something else?
Often, though a lot of these have the same outward appearance and specifications, slightly different components are used inside. This means that some ROMs do not work on one machine, but works ok on another. There are a couple ways round this if you supply more details (but can't promise!)