I don't have an autostop.

Alright, the button is now working as it should. All reels stop properly, without extra button pushes.

*EDIT* -------------------------------------------------
I was asked to post what I did to fix the button.
I took off the back to expose the circut board.
Basically I sprayed the **** out the button by the board and at the
button so it was dripping, then I pushed the button constantly
against a paper towel until it was dry. Reinstalled it and it worked.
*EDIT*--------------------------------------------------

I noticed on the sound board (located at the bottom of the machine under the power supply) that a LED lights blinks with the sounds. This light lights when the right button is pushed, just like the other two. But the sound is muted.
SO I believe that the sound signal is reaching the sound board, just not loudly like the rest.

The only sound that is not loud like the rest of the machine is when you press the right button to stop the reel. ALL other sounds are fine.