20x4 SainSmart LCD2004 i2c faulty board or not?

I recently bought a 20x4 SainSmart LCD2004 which has a build in i2c board. I hooked it up and found a up-to-date library. I got it working and printing string easily.
HOWEVER! Anytime i print anything in the bottom 4x1 area at the right of the screen, it gets duplicated to the 4x1 area just above it (and vise versa). I’ll try to show with a diagram below.

XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXBBBB
XXXXXXXXXXXXXXXAAAA

'anything printed in ‘AAAA’ gets duplicated in ‘BBBB’ and anything printed in ‘BBBB’ get duplicated in ‘AAAA’.(also Sometimes the duplicated characters would be capitals or completely different chars) E.G “Hello world” printed at (9,3) shows:

XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXorld
XXXXXXXXXHello World

As it turns out if i scroll strings through this ‘bugged area’ the LCD output is fine, its just when the strings are printed directly to the ‘bugged area’ that it them bugs out in this unusual way.

I’ve experimented with different libraries hoping it was in the code, however the problem persists. I haven’t seen any mention of a problem like this in any forums I’ve searched.

So is it something n the hardware (meaning i have to return the LCD) or is there something that i am doing wrong or have done wrong or can do right to fix it?

If you tried different libraries, I think you did the right thing. There were a few other questions like this with a faulty displays on the forum.

It seems like a bad contact inside the lcd, or a badly decoupling of the power, or a voltage that is too low.

If your voltage is good, the display is faulty.

Anytime i print anything in the bottom 4x1 area at the right of the screen, it gets duplicated to the 4x1 area just above it (and vise versa).

Your two examples show different locations for the error. As this could be due to an addressing problem it is important to know exactly which screen locations are the ones that are affected in order to determine possible causes for the phenomena you are experiencing.

Don

Edit:
Part of the discrepancy is the font used by the forum. Here it is in monospace (use the ‘typewriter’ button) but there still is an alignment problem.

XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXBBBB
XXXXXXXXXXXXXXXAAAA


XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXorld
XXXXXXXXXHello World

solved. returned the component and bought another one. without changing any code the device works perfectly, it was a faulty i2c board.