I have an Astro that is acting up on me. It will run great for a day or so and then stop and restart with a light tap. Also, twice it has stopped while sitting on my desk but again it will restart when given a light tap My thinking is that the hack spring is not adjusted properly. I have not adjusted many watches with hack springs so I came up with my own method, which is perhaps not a good one. When the watch is fully assembled without the dial, I install a battery in the pillar plate. I loosen the 2 screws slightly on the hack spring and move the spring so the watch stops humming. I then tighten the two screws. After that, I p[ress in a hack plug and if the watch is humming again, I put the dial and hands on and case the movement. Once the movement is in the case I test the watch to make sure the second hand does not move when the crown C ring is lifted. Even though the second hand does not move, I do hear a whirling sound. Maybe I am not suppose to hear that? Comments will be appreciated.