Touchscreen not working after glass replacement

Replaced JUST the glass on the iPad 4, kept the original apple LCD which was fine, used a hairdryer quite a bit to remove the adhesive, and also to blow all the dust off. Put it all back together, the screen powers up and everything, however it's not responding when i touch, or swipe the screen. I've removed all the plastic films and protectors, taken the cable out and put it back in 4 times, any suggestions? It's for a customer so is urgent that the problem is resolved, would the heat have killed the sensitivity in the actual LCD?

Thanks

Jacob