New Scout 1.1 with hum issues, kind of fixed?

So, I just got a Scout 1.1 off Craigslist from a fellow audio freak. When I plugged it in and got it all set up, I went to listen to a record and the hum was so bad that the table was basically unlistenable. LOUD and overpowering the music, even.

So I did some research. I connected the arm/junction box to the phono pre and that helped a little, but I wanted to try something else. I decided to try adding a ground wire from the bearing nut on the bottom of the plinth to that same terminal on the back of the junction box, and, sure enough it made the hum just a little quieter... so, I went further and decided to add a ground wire from the motor to the same terminal again... same result... even quieter. There is still a very light hum but no where near as bad, and if I disconnect the wires from that junction box, that super LOUD hum comes back. So, this is obviously helping in some way.

Does that mean I need to ground something else????? I'm relatively unqualified, definitely not an electrician... is this normal?
It's a Shure M97xE with the LP Gear ViVid Line stylus.
Ensure your cartridge pin connections are correct and making a solid connection. Ensure the cable from the RCA box to your phono amp is well shielded. Try replacing it with another to test. Make sure the stylus is pressed home fully.
Anything less than perfect contact can introduce hum. Just one of a long list of possibilities, but it is on the list, so might as well check it off.

Clean thoroughly with ordinary rubbing alcohol. Sounds decidedly low-tech but that is what Keith Herron recommended to me and lo and behold, it works.
You also might try sanding the pivot pin the arm sits on. There was a short period where the unipivot came coated. With that coating the arm has no way to ground itself. I had this issue on my Prime and was told to use very fine steel wool until I saw bare metal. You may be able to find the thread on the VPI forums.

Sometimes if you move the motor a bit it helps also try a mouse pad under the motor. Has the tt been serviced lately( lube and oil).
Good luckĀ