Ghost cassette in tape player

[sams0091]

1999 Buick Century

The cassette deck has the "Tape In" indicator lit on the front of the unit but there is not a tape in. The metal tray that accepts the tape is in the "up" position. I've tried holding the Eject button until the unit cycles, but after it cycles it doesn't change anything. I've also tried pulling the fuse for the radio and disconnecting the battery cables in order to powercycle the headunit and all it does is reset my clock (my radio presets remain). I've heard that there is a microswitch that senses whether or not a tape is in that could be stuck, but haven't been able to locate it inside the deck. The most curious thing of all is that when I try to switch the radio to tape mode via the "source" button, it won't switch over to it.

Please let me know if the deck is just screwed or if I might be able to powercycle / reset the unit somehow to make it realize there is no "Tape-In".