fast way of testing 4g 4s LCD other than installing completely

Hi There

We are a wholesale company that provides mobile phone spare parts to labs and cellular operators.

We sell a lot of iphone 4\4s LCD.

we always test our goods before supplying to our clients,

my questions is, if there is a way of testing the 4\4s LCD with completely installing the LCD to the phone?

because this method takes us a long time and can easily destroy the mainboard.

the big problem is the pressure marks on the sides of the LCD, which can be seen only in full installation.

thats why the use of testing "machine" or flex LCD extender do not help.

Would like to hear your suggestions.

Thank you very much

Raj