I have a RadioShack Pro-18 issue. While unit is scanning the screen has a garbled mess of various characters. I posted a pic. When it locks on to a frequency it stops and shows what is playing. No issues in menu just while scanning.
First off, I don't know what the problem is. However, with other electronic lcd devices, I find that experimenting with battery removal, battery replacement, and power supplies is a place to start. I would also totally remove the batteries and plug in your USB cable to either your laptop or the power adapter and turn on the scanner and run it that way and see if you get the same scrambled screen. My experience with lcd scrambled screens on other devices seems always related to battery and power issues. You might also need to do a hard reset and then use the iscan software to reload your scanner. I've also heard of putting a device in a freezer for an hour cures such problems LOL. Hey, whatever works!
Its your MicroSD card,replace it,this was happening to mine,I replaced the card,reloaded everything and Im good!
From the point you get your new card,load the card by taking it out and using an SD card reader/writer from that point on.