Fender 212r is on but isnt making any noise

sounds like bad caps and maybe a failing output transistors. Use Deoxit contact cleaner too.

After ruling out guitar wiring or bad cables...
Try the 2nd input on the amp
also
Is it on both channels, or just one?

Find another speaker to check it with. I've had several fender amps to blow their speakers during loud playing.

... do you, by any chance, have non humbucking pick ups on your guitar? Just curious...

You have an internal component heating up and loseing contact. Take it to a Fender service center for repair.

If the humming ONLY happens when a cable is plugged into the amp, the problem is in the cable or the guitar. Poor quality cables or wrong cables will result in hum. Defective wiring or connectors in the guitar OR having the guitar near a source of magnetic fields will result in hum. We cannot diagnose these possibilities remotely.

yes,, Pre means before powered or amplified ,, so yes you can do this to a powered mixer, just be sure that the power is off before making any connections,, without the ground of the rca cable touching , the blast to the speakers can invert the cone !!

There is something resonating with that note frquency. Often the grille or wiring inside will rattle at certain frequencies. You need a sustained source of these frequencies to find what is causing the noise.

The Fender Stratocaster (in common with all Fender guitars) has passive pick-ups so should be plugged into the no 1 socket.
Whilst it will work in the No 2 input socket this has lower sensitivity and is intended for use with guitars that have active (battery powered) pick-ups.