I buy it a cheap second hand tomtom 730 with case , but in startup screen show me tomtom 930 , in tomtom home tomtom 730 .
The touch screen not working .
Is posible if i change the display show the model of the display tomtom model not the electronic componets ?

The only difference between these 2 devices is the internal memory (730 2Gb, 930 4Gb) although both can run up to 32Gb SD card anyway, and what map(s) were originally supplied with it.

Re the touchscreen, you need to read around here tutorials/touchscreen-calibration-t10957.html or possibly replace the screen/digitiser