That's why I'm asking if someone has an exact picture of where it is, so it can show me where to get it exactly. I know that plates have a very small blinking dot when they are found on the itemfinder, but I didnt find anything like that.
And another thing, where can i get TM73 Thunder Wave?
I don't have an exact image, but if you really cannot find it, then I suggest you try your luck underground.
However, you can find TM73 Thunder Wave at the Fight Area, but in order to obtain it, you have to have a certain amount of Battle Points.