I'm new here so please pardon me. I have a 2004 Prius with a "screen that works"; it's blank for the majority of the time, but when I mess with the volume or climate control it will have a delayed or randomly-seeming alert. It won't show navigation and won't let access any of the buttons. So, what exactly is screwed up here so I can get it fixed? Please help!
Sounds like you will have to get your screen replaced or fixed. If your good with a soldering iron you can fix it your self. Hobbit did I nice write up on the whole thing. Prius MFD You could get someone to do it for you if you know someone. Or you can pay the dealer about $500 or more to get a replacement.
This sounds like symptoms of the MFD design flaw in 2004 and early 2005 models. Toyota USA may pay part of the cost if you ask.