On 21/09/2020 12:41, Tom Hunter via cctalk wrote:
The problem I am seeing is that 3 keys ("h",
"j" and "y") are permanently
pressed.
I'm not familiar with this keyboard, so despite having fixed lots of
other types, what I'm about to write is no more than musing and may be
inapplicable drivel, but...
A friend once spilled a glass of wine into his keyboard and had a
similar problem. I've seen the same from a cola spillage. Washing it
fixed it. Can you see if there are any spillage residues in there? IPA
isn't always better than water and detergent - though you might want to
use it as a water removal agent afterwards.
As I imagine you've already realised, the keys are adjacent and likely
share a track.
I looked at the pictures. Can you get at the other side of the circuit
board? If the it's fibreglass or even SRBP with copper tracks, maybe
you can get at the tracks to the 'h' etc keys and cut them with a
scalpel or craft knife to isolate them to see where the resistance
really is. Before cutting anything, obviously make sure you can get a
soldering iron in there afterwards to bridge the cuts.
--
Pete
Pete Turnbull