hi every one
i used this 2*16 lcd and connected it to my atmega16 in a project but half of the pixels of lcd on its right side are not responding and just show some dots.
here is the picture:

i used 4bit coonection forn atmega16 to this lcd. but looks like ni data is being sent to those pixels (( on the right side of lcd)) how ever i just assembeld this form the proteos chematic and in that sotware the whole project works very well whit no problem but when i want to do the same thing by myself in my circiut i see that some part of my lcd show full pixells instead english characters.

a friend told me that i should connect those 4 free pins of my LCD to gorund . and i did this bu no changes happened for it.

please help... how can i fix this...??

 

It looks like your LCD is damaged.

The DB0 to DB3 pins must be grounded when you are only using DB4 to DB7.

 

LCD damaged, pin wrong, possible pin grounding out or touching another pin.

 

Your solder work looks kind of dodgy. Heat the lead and PCB up at the same time, and do not use to much solder. Some of the solder blobs are to big. I think that either component lead or PCB was not heated properly when solder was added.
Do a Google search on the phrase how to solder. You will find a lot videos on You Tube. But also other stuff

 

The LCD display character 5x7 matrix is missing columns.

One can't achieve that even via software programming of CGRAM so the LCD must be bad.

 

One of the columns begins to fade mid-way through which would also seem to point to a failed LCD being the only option. I've heard of lines like this appearing due to overvolting of the LCD controller, though I'm not sure if it would display any text if that happened.

 

I tend to agree with those who suspect that the display has been damaged. The LCD controller is probably ok but the internal display ram and/or the column driver devices appear to be damaged. It is also possible that the zebra strip that connects between the PC board and the LCD glass has been damaged or has been mechanically disturbed.

hgmjr