2007 dash/speedo went dark

congrats and welcome!
some have had a bad solder connection in the display. you can have the trouble codes read at a dealer.

 

The HUD (heads up display) dash display goes black when it doesn't reset upon IG on or it is blown out. It may work after several restarts, IG on..

My 04 gen2 HUD will go black on cold days. Once it warms up it works on a restart. It is doing that more this winter.
One thing is it takes 3-5 seconds holding the power button to shut it off with no display. If it shuts off immediately that may lead to a different diagnosis.

First try this, expose the 12 V battery. Remove the red +12 v connector cover, Unplug the larger connector. The release clip is on the bottom.
This will reset the EUC's. After a minute plug it back in.

The reason I suggest the +12 v connector is it makes for a cleaner connect. The ground connection screw sparks a lot.
Make sure it it clicks when inserted. If it is loose nothing happens when you try to start it up.

If that doesn't work then the display has to be repaired.
You have to dissemble the dash and pull the display module. Youtube has instructions.

On eBay there is a person who repairs the module if it has a bad reset circuit for $98.00

Otherwise you have an expensive repair with Toyota.

 

You probably have two issues. One is a well-documented problem with the CM (combination meter). Toyota has a nine-year warranty extension on this, but it's expired for your car. Your best option now is probably the $100 repair noted above.

The bad CM will not give you all those warnings. Something else is going on, and you need the diagnostic codes. (Next time you want to get a diagnosis based on codes, do not erase the codes.) Autozone may not be able to read all the Prius-specific codes, so you may need to go the dealer or buy a Toyota scanner (look up Mini-VCI for an inexpensive option).