22 Dec
2011
22 Dec
'11
2:34 p.m.
On Dec 22, 2011, at 5:05 PM, Eivind Evensen wrote:
I have an Amiga keyboard (pcb says A3000) where the
four
keys 1, q, a and z doesn't work. The rest of the keyboard
functions well.
This happened after a longer period where I didn't use the keyboard.
Does anybody have any ideas of things to check out to try
to get this working again?
Could be one of the outgoing or incoming matrix lines being broken. Try seeing if you can
ohm them out. You should be able to determine which line is a likely candidate by
checking which one goes to those keys (they're all in a column, so it should be
relatively obvious looking at the PCB).
I've not seen the internals of that keyboard, but most keyboards I've seen have an
internal ribbon cable connecting the matrix PCB to a separate controller PCB; you might do
well to try (carefully) reseating that cable, as long-term exposure to humidity can
corrode the contacts, making them more resistive.
- Dave