Hi there,
I just bought a 464 in great condition.
It's medium-sized board (MC0044D) with a membrane keyboard (Z70211)
Unfortunately, at power-up (and later) the keyboard is sending complete garbage.
Power up :
963RUN"
+ 8 different symbols + reversed "?" repeated until the buffer fills... then I can press Esc
Here's a sample of what the keys do, there seems to be some logic here :
Esc : works normally, *break*
Tab : nothing (caps lock, shift too but that's normal)
Large Enter : *break*
Copy, keypad 0, 1, 2, 5, 8 : " 85120"
keypad 7, Del, Clr: working !
keypad 3,4,6,9,enter : nothing
P,Q: nothing
W,C : 5 symbols (the same)
T,V: 5 other symbols
Y : 4 symbols
E,R,U,O : 1 symbol
I : 3 symbols + return
M,',' : 3 symbols (the same)
What I tried :
- fully cleaned the membrane
- tried without keyboard plugged in : no garbage characters
If I read some other threads well, it may not be the AY because there's no issue when the keyboard isn't plugged in.
What should I try next ?
Thanks !
Answering myself : it's the membrane !
I swapped it with another 464 and all the problems disappeared.
I can't see where the damage is on it, it's a shame. Given the symptoms, would it be hard to repair ?
Sometimes they have just got sticky from dirt. Clean it with a soft cloth and soapy water and it may work again normally.
Bryce.