HP 110 "garbage" on screen

[Klaus Overhage]

As far as I know the display board gets the data to the single picels. The decision how to display a character is already made in the LCD controller board in the lower main part of the computer.
In the Hewlett Packard Journal July 1986 is a photo of it on page 27.
Fig. 2 "Photograph comparing LCD controller board space in The Portable (I) to the size of the 25-line LCD controller hybrid used in the Portable Plus (r)."
https://www.hpl.hp.com/hpjournal/pdfs/Is...986-07.pdf

On Page 25 the is this sentence "To support a full screen of graphics, it is necessary to have more memory than the single 64K-bit static RAM used in The Portable."
Maybe this 8 kByte RAM or a connection to this board causes the problem.