Broken LCD Cannot Detect Touch Sensor

[apislerr]

hi, my iphone 4 has been broken lcd. After that i changed back new LCD iphone. But , the problem is when i touch alphabet "p" at keyboard, it cannot detect my finger sensor. What the reason?
thank you for your respond.

 

[mKTank]

hi, my iphone 4 has been broken lcd. After that i changed back new LCD iphone. But , the problem is when i touch alphabet "p" at keyboard, it cannot detect my finger sensor. What the reason?
thank you for your respond.

The LCD panel isn't responsible for touch input. There is an entirely different layer called the digitizer whose job is to recognize touch input. I suspect it got damaged along with the LCD panel but wasn't replaced.

 

[Applebag]

See if the P button works in landscape mode. If it's not clickable in either orientation, it could be software which could be fixed possibly with a hard reset (hold lock button and home button together for 9 seconds). If not, it's a bad Dig. The good news is that you can only replace the digitizer/LCD as an assembly because they are fused together at the factory. You can find replacements on eBay if you were so inclined to attempt a repair yourself. If that's too daunting, let me know and I can provide you with more options.