Anyone have any idea why my LCD display looks like this?

[labbie48]

Trying to get a second LCD display to work with only partial success. Both displays are identical from the same manufacturer and work perfectly when hooked up to one board but when I load another sketch to a new board I get an incomplete printout. I've tried 3 different boards with the same results. At this point I'm pulling what little hair I have left out.

[Bill Brower]

There is usually a blue, squarepotentiometer on the I2C daughter card that can be tuned for the best screen.

[labbie48]

Not the problem, tried that and like I said, when I hook it up to the other board it's perfect. Don't know if it's the sketch or what.

[Demusman]

I've had issues like that when the power supply I was using wasn't strong enough.

[labbie48]

Not the power supply, went that route already.

[randy]

I have seen the same thing. I have 3 working great but when I added a 4th I got the same problem. Tried several LCDs and NodeMCU boards always with a block on the first character of the first line or two. I was never able to get it to work, so I stuck with 3. This was a year or so ago. I also never let Greig know, because I wasn’t convinced it was a plug-in issue. You might let him know to see if he has any thoughts.

[enigmatheatre]

I can't say I have seen this happen here on the 3 displays I use. I don't think it is because of the number of displays in the system as Randy and I have 3 working fine. I think I have another display somewhere so will look it out and try it too.
Can you please send me a debug of you sending the data that is causing this on the display to see if I can track down the problem.

[X10joe]

Did this ever get solved? I have this problem too.