Can't Change to Disc or Tape Mode anymore

[RX Man 7]

I have a 2006 RX 400h.  had it 3 years as of last week. Today I let someone move my car for a work thing. When I got back in the sound system was turned off, and I didn't use it while I was in the car. When I got ready to leave for day, I turned it back on and the radio came up. I pushed the mode button on the steering wheel to get it back to disc, so i could listen to music and use the phone's google maps to get me back to the right interstate to go home ( it is bluetooth synced for phone and audio), but it would not go to "DISC" or "TAPE", I pushed the TAPE and DISC buttons and nothing. Only the AM or FM buttons will work now. It shows on the phone that 2 devices are connected by bluetooth, but I cant get it to DISC to use the phone.  Now the only thing that I have done differently today,  since I got it, is use the air conditioner for short times and turn it off. could turning it on and off too much cause this sort of thing to happen?  Did I drain the battery too much? Is there a fuse out? Was it something they did? This is truly bizarre, can someone help?  Please and thank you.

[RX400h]

Maybe you should disconnect the battery and reconnect it. You would have to reset the windows but that doesn't take long.

[RX Man 7]

Acknowledged.  

So do I disconnect both terminals or just the positive?

Oh, and when I got in today, it synchs with the phone, but still can't change modes. Could this be an indication that the battery is coming back to a full charge and I just need to give it a couple days for everything to return to somewhat normal ? 

[RX400h]

I would disconnect the negative, then positive terminals for a minute or two. Make sure the positive cable does not touch any grounded component. While disconnected, clean the posts and cable connectors with a wire brush tool you can get at any auto parts store or maybe Walmart. There is also an anti-corrosion spray that can be applied after reconnecting the cable clamps. 

How old is your battery? Sometimes a weak battery will cause weird issues to surface. The battery should have a date sticker on it. If the battery is more than 3 years old, you can have it load-tested at most auto parts stores. They will fully charge it before the test.

[beapyeap]

Did OP ever get his DISC or TAPE buttons working? I have a similar problem with my DISC and TAPE buttons being unresponsive on my 2006 RX400h. I tried replacing the fuses and disconnect/reconnecting the battery per this page, it's been a couple months now and they're still not working, though everything else with the radio seems fine.