one beep, no power, key fob works = SOLVED

2006 with smart fobs
Unlock from the fob works.
Doors open light works.
Headlights work.
Power button gives one beep, medium length, then nothing.
No light on the power button.
No lights on the dash.
No lights on the MFD.

I took the interior apart to do sound insulation. The floor area is done. I put the NAV and DVD units back in. New 12V battery, 10 minutes new. The car has been sitting for a year or more during the upgrade process. Lots of other items besides the insulation.

I am a bit paniced, because I need to be able to make the car move tomorrow to get some other cars moved around. It's rather urgent.

I am running searches and looking for solutions to try.
The fuses all look good. I have not tried any relays yet. I do have spares.

Is there some component that I unplugged that needs to be reconnected to make it all work?
Is the hybrid battery dead?
How would I test it?

Help is greatly appreciated.
Thanks.

 

Update: The center console, from the back, pull off the rear cup holders, there is a white electrical part screwed to the backside of the center console, about the size of your palm.

I plugged this in and the car went into ready mode. Or mostly ready. Dash is good. Power lights are good. MFD is good.

Transmission will only go into Neutral. I need it to go into Drive and Reverse.
Your help is appreciated.

 

Update: Turning the car off and on again fixed it. Car starts, goes into drive and reverse.