The MID unit on the dash is just a display - no audio etc. inside it at all. You still need to isolate the fault to the actual radio (either inside the Business/Professional CD player or in the trunk - depends on your model) or the actual MID unit before replacing anything.
You might want to leave Fuse 75 in place and start unplugging the various modules listed here (while monitoring the sleep current): -
https://www.newtis.info/tisv2/a/en/e...5-fuse/hWIC4cC
Good Luck!