I was not wise.
It was driving me nuts all day. Found this youtube video that detailed removing the keys
Took a bit of courage, you have to really BEND the key to get it to pop off and come free. But it worked!
And dammit.... wouldn't you know it, it was a CAT HAIR, stuck underneath right on the sensor. The whole operation took about ten minutes as I was REALLY CAREFUL. Anyway, would not advise unless you have steady fingers and good lighting.
Finally the L works again!