@alex.martin, you do not have to check the contacts inside the screen as this is not a contact problem and cannot be fixed. You are dealing with a defective screen and we will send you a replacement, please PM me your address and some proof of order.
Contact problem are usually manifested in contrast problem or the screen being completely blank (a.k.a. the microcontroller is having trouble accessing the screen’s memory or the screen’s power supply contact is bad).
If there are dead pixels on the screen, that cannot be fixed and the screen has to be replaced.
I will mark this topic as [SOLVED]