Charged battery, but doesn't even try to start.

It does sound like a secondary ignition circuit problem. Id have to agree with members that said check the bulkhead on the firewall going into the passenger compartment to the ignition cylinder (key).
The steering column under the dash also has another flat connector to check for bad connections, going to the key.
Tough to diagnose when not there to help and a lot to consider when everything everyone has given so many logical possibilities.
Hang in there, you're in the right place for advice!