Replacing Radio and Main Function Display Won't Turn Back On

I received a new Sony radio for Christmas and upon trying to install this radio into my 2005 Prius, I found out without a special harness the radio will not function properly in my car. This isn't really the issue anymore as much as after I had finished gently placing the unplugged MFD aside during the attempted installation and when I put the MFD back in its place and turned the 05' Prius back on, the display did not turn on and has not turned back on since I initially removed it. My knowledge about how the MFD functions is minimal at best so I don't know if this is some sort of anti theft mechanism and it needs unlocked or reset but I am at my wits end after the radio installation failure. As a side note, when I have reinstalled the original radio the Prius came with, that radio as well as the MFD do not turn on or perform their intended uses. Any help would be greatly appreciated to relieve this Christmas AND Birthday blunder, its been a frustrating last 3 days.

 

Thanks for the input here. I'm going to return the Sony radio I was given fro Christmas and just put the car back together as it originally was. I will re-check the plugs to make sure they are all the way in. I was very gentle when removing the MFD so I am hoping I wouldn't have damaged it in anyway. I don't think I did. Is there any special way to turn it back on after removing it or should it just turn back on as the car does. By the way, my original CD Changer (Radio) also does not turn on at this point after being plugged back in along with the MFD. Thanks for any help.

-RS