Can't get a CFAG12864B-TMI-V to work


New member
I've tried to solder a 128x64 graphic LCD to my parallel port and a molex (for 5v and ground), exactly like on this drawing:

But when i connect the LCD to the molex, i get this on my lcd:

The left blue border's width is 4 pixels, then a 2 pixel wide white bar, and the horizontal bar is 7 or 8 pixels high (can't see it exactly).
The white pixels become dark when i turn the contrast to a normal setting, the white pixels are 'off', but the pixels i drew blue here don't seem to get power.

Sometimes, when the lpt plug isn't connected, random pixels go on and off on the lcd, and then there are 3 types of pixels:
- Pixels that are clearly on
- Pixels that should be off (appear a bit dark)
- Pixels that don't get power at all (don't change even if i set the contrast to it's highest setting)

When i try to write anything on the lcd, nothing happens.

I'm absolutely sure my LPT settings are correct, and quite sure too everything's soldered properly.

What could be the problem? Is the LCD just broken?
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.


New member
The main problem was I had my LPT port set to EPP in stead of EPP+ECP.

But here's another problem:
When i set the contrast rather high (so i see the 'off'-pixels a bit purpleish) and print the following bitmap to the screen:

This is what i see on the screen:

It looks like the screen has a whole lot of dead pixels, but if the pixels above/below the 'dead' pixels are all on or off, they look like they are just 'off'.
Last edited:


New member
I found out what the problem was, a corner of the lcd glass is broken, and it arrived here in that state :mad: