My touch screen is not responding. - LG KM555 Cell Phone

Most common problem of a touch screen mobile is when :

1. dropped the phone into high range.
2. water damage
3. and when the touch screen panel is broken.

(D-I-Y) if you have the parts with you,unscrew all sides were screws are located at the back housing portion using T6 precision screwdriver,just lift up the upper portion of the housing,be careful cause most of touch screen is attached with a strong adhesive towards the LCD,lift up the clip of the touch screen flex connector and pull it out.now you can remove and replaced touch screen panel on the upper portion of the housing and assemble it,then try if its working properly, some instances that the replacement parts has a factory defect so you can go to the parts supplier and ask for a change item.

but if you can't do it on your own,just bring the mobile to a phone service technician nearest you.