I received a 30 day notice, with no reason why. 3 days after I received my 30 day notice, I sent my rent to the management company and cashed the check. Does that make the 30 day notice void.

Bob

No, it only means that you needed to pay the last months rent on your rental.

Assuming you did not pay first and last month when you moved in.
If you paid first and last month when you moved in, you should ask for it back.

But you still have to pay for the last month you stay,