I have purchased acouple of shelly 4x16 hd44780 backlit lcd from a guy on ebay. the problem was that he didn't have a schematic or any info(i didn't know this until it arrived). he sent me the generic one used for almost every other 4x20 on the market. My lcd's have a 15 pin input while most other 4x16 and 4x20's have 16 pin inputs. this i am hoping is the problem. if you have any info on the shelly lcd's i would really appreciate this. thanks a ton!