Keyboard dying? rogue keys.

Question

As yu will prbablly see while reading this, I'm having a very annying prbllem with the o, ll, k, and .. keys n my keyboard. They either don't wrk at al, or spray letters all over the plllace when I press them.
It al started with the o. The capital O onllly woorks when I press the right shift key, not at all with the lleft ne. It went dwnhilll frm there. Now the keys mentioned above are giving me probllems. Sometimes they woork fine, and sometimes, llike right nw, they suck. The capitall O, hoowever, never wrks with the llleft shift key. The lleft shift key works with allll other lletters, though.
At first I thought it was just crud stuck under the keys, especially since they're in the same area. Lord knows there's probablly spare change stuck up under here smewhere.. But that doesn't expllain the capitall O thing. Hoow can I get underneath the keys to llook for crumbs? Is this a logic booard issue (please say no). I can't any related info in the powerbook discussions..
Help! Thoughtlless passwrd typing is a luxury f the past!

Answer 1

You probably need to replace the whole keyboard, which is somewhat difficult.
The construction of the keyboard assembly makes a few crumbs unlikely to be a problem. Under each key is a scissor action spring assembly and an elastomer bump. This sits on top of a pretty much sealed plastic sandwich sheet of electrical contacts. Minor debris really can't affect the electric contacts. Enough liquid can seep in through the edges and shorts out the contacts. Unfortunately, the electrical contacts for all the keys run in a matrix and come together into only a handful of conductors (6?) that go to the keyboard ribbon cable. If one of the main conductors goes bad, a whole group of keys goes bad. In theory, just wear and fatigue in the plastic contact sheet could cause erratic key operation. You might also have a bad cable or connector.
FWIW, I usually just turn my PB off and turn it upside down while blowing on the keyboard to remove loose debris.