Touchscreen do not work at all!

Hi

My brother have a first generation iPhone. About a month ago, the home button stop working, we gave it to a service center (3rd party, not Apple) and they've charged us 150USD for replacing the LCD.

But, now, less than a month, the touchscreen stops working.

At first a horizontal line appear on top of LCD and slowly, touchscreen

completely stop working! :(

(You can see horizontal line in this photo)

Can you help us fix it?

I know how to open the iPhone (in fact, I've done this once), but I don't know where the problem is coming from.

Thanks

PS: Sometimes, a small portion of LCD (above slide to unlock area) work and I can slide the button a bit.