When the green light went out in my wife's radio in her '00 4Runner a couple years ago, I asked our local toy dealer how I needed to go about having it serviced. They told me they would have to send the radio off to be repaired. Said it would be at least a couple hundered dollars just to send it off! A new oem HU was roughly $600 +. Crazy I know...
So I started searching the Yotatech "Classifieds" section and Ebay for a used oem HU just like the one she had. (My wife did not want an aftermarket HU, so that was not an option.) Luckily, I found a member on here that had removed his oem HU to install an aftermarket one. He sold me the oem HU for only $25 shipped

. It's been working flawlessly for 2+ years now.
So unless you want to go aftermarket, sounds like you'll have to do what I did and search for a used oem HU. Good luck.