Don think is the problem of LCD. If possible do test it on a working board such as SK40C, don solder it, use header or socket to stack it. I seldom see broken LCD though my friend do get a faulty LCD once, but that might be due to wrong interface he did earlier.
Are you sure there is 5V from voltage regulator, I know you checked it Just to makesure again, because this LCD works at 5V, at 3.3V or below it cannot function, tried that before at least we the LCD I have