Analogue-sequencer

> is there any reason why installing the memx board would have affected 
> my display? 

No. The display is a separate module with its own CPU.

> The bottom half of the top top line is gone and the bottom part of 
> the bottom line is also missing - it looks weak too

And it was fine before you opened the case ?
This sort of failure has happened to a few modules.
It could be static damage to the display module.
Or maybe physical shock has affected the connections between the display
module board and the display panel.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com