Trouble with H4780 LCD

Hi everyone... I run Mega2560 with H44780 20x4 LCD screen... he worked perfectly and later (maybe after wrong cabling or stupid thing only a "totally new in electronics" can do, my screen look like this


| ############| | ############|- |####################|

|####################|

instead of

|####################| | | |####################|

| |

my screen as grilled or i can fix it.??... the hello world exemple sketchdon't work no more...i read a post about firmare of the lcd that can be replace...is it a way to go ? Someone had already this case? thanks in advance