Cleaned the phone with alcohol wipes, screen dead?

[mzzxx11]

I've cleaned the x10mp with wet wipes which contained a bit of alcohol, to remove fingerprints & grime.

Now, there is a rectangular region in the middle of the screen where touching produces nothing. There are no dead pixels, as far as I can see, just touching there isn't picked up by the phone.

Pressing anywhere else on the screen works fine.

Any suggestions?.

TIA