Ignition Key will not turn

[Alfred Bernel]

Helping out Son-in-Law with his 02 Envoy.  Steering wheel turns freely but key will not turn in ignition at all.

 

Short history

Few days ago he found he could not turn key all the way to off position and remove key.  Didn't really worry about it, as he could still start the truck, so let it be.  A few days later he either left key on or left something on and killed the battery.  He started searching youtube and found video that showed him to hit a button on underside of steering column (which I have found to be the steering lock mechanism) and he was able to turn the key to off and remove.  Well now the key wont turn at all.  

We have checked the switch that is down by the shifter and it seems to work properly (took it out, and the little white nipple is not gummed up at all, moves in and out freely with the plunger depressed).

I was starting to think maybe the spring in one of the catches came out or something - so saw where you could use something to vibrate the tumbler while you try to turn the key to get it to turn far enough to remove and replace.  However, I am curious about the steering lock mechanism and him pressing that button.  Is there something that needs reset, or relocked or something?  I know there was an issue BEFORE he pressed the button, but trying to see if pressing the steering lock button compounded the problem or not.

 

My other concern once we get the cylinder out to replace it, is there is a small wire harness (like 2 or 3 wires) that runs up from under the steering wheel cover to the top of the tumbler.  Is this a chip key setup?