Quote Originally Posted by leonel
When i put all to +5V my lcd doesnīt work.
Come on, be more specific.

What do you mean by "doesn't work" ?
In one post you say there are only black boxes,
in another post you say the problem is with the backlight.

and what is the reason for having 4.3V and 5V as supply voltages?

Have a break re-think your question and be as specific as possible on your next post and we will find a solution.