Nokia 1100 LCD Shows nothing

Hi to all! I need help with this display. I’ve soldered all pins (shorted vddi, vcc and led+), connected to the breadboard (with needed resistors) and then to the arduino pins 8, 9, 10, 11.
I’ve downloaded from a russian website the circuit and the sketch and modified few things only in the circuit:
-Instead of 4 resistors (1.8KOhm) I’ve used 4 variable resistors setted to 1.8KOhm
-Added one LED for each VR.

When I switch on the circuit, LED on pin 11 lights up with intermittence, as data communication active. 8, 9 and 10 are off.

I’ve checked all connections, but the display remains empty. I’ve noticed (only after) that is appeared a black line on all the display border… Is it definitely broken or there is something else?

Attached the circuit that I’ve followed.

Thanks to all!!

I’ve forgot to say that the library is in the right place and this is the video: