problem with control panel emcotronic TM02

Just joined this forum so i will introduce myself first.
My name is Danny from the netherlands and recently purchased my first secondhand CNC milling machine (Emco VMC-200)
I am planning to produce my own parts for my hobby company that is specialised in laser parts for lasershows.
currently I have a daytime job where I work with CNC machines (Fanuc and Mazak both milling and turning)
Next to the job and company I finished my first milling and turning study and now half way the second CNC turning and milling study.

Now on to the problem.
I have a emco VMC-200 with Emcotronic TM02 control.
it seems like the control panel is not working correctly as i type in some letters sometimes the correct one appears on the screen but most times another letter appears.
altough everytime i push in a button the letter on the screen blinks so it is getting a signal but not the correct one.

i already replaced a few buttons that appeard on the screen often but this doesnt solve the problem, it seems the buttons are working correct but the signal that it gets is incorrect.

Here i have a video of the problem:
emcotronic tm02 keyboard problem - YouTube

Hope anyone knows a solution for this problem or has some advice that may help me with this problem :)

Best regards,
Danny