Touchscreen not responding - Sony Ericsson G900 Smartphone

The reason your phones touch screen is not working is simply because there is a problem with the flexi of the phone.

If the screen is not damaged in any way, then the assumption of it being the screen is absolutely correct.

To fix the flexi of the phone;

1. Get the appropriate screwdriver,
2. remove the battery, the battery cover, and your sim,
3. Turn the back of the phone,
4. you will see five rubbers,
5. pick them off with a pincher,you will see screws under them, unscrew the phone,
6. Get a credit card and slip it through the line around the phone then apply a little force in separating them apart,
7. you will see the panel of the phone, carefully lift it up,
8. you will see a flexi that runs through the screen to the panel, carefully detach the flexi from the panel,
9. unscrew the screen of the phone, remove the flexi connected to the screen also and replace it.
10. Reverse the process to reassemble the phone.

Hope this helpout........