Even the permanent magnets, its magnetic will gradually become weak, professional magnet appliance at regular intervals with special equipment operation. magnetization " If two upstairs in the proper temperature, humidity and strong magnetic field and magnetic radiation and other factors affect the environment, to the magnetic almost can never keep down." Can tell you, even with this condition, magnetic will become weak, reference may be made to physics "entropy increase relevant conclusions," magnet is orderly arrangement molecules, but as time goes on, the disorder inevitably increase (this is the second law of thermodynamics), so no matter how also won't last forever!
        Tip: electromagnetic rbis in the point on the tape timer is not clear, this is too weak magnetic with permanent magnets related?
        Even the electromagnetic force magnet weakened rbis timer, in terms of the current 9V voltage still can rise to active function and not just don't play, only small, generally for strength not clear on the error analysis can be considered as the toner cartridge paper cannot hit clear place, anyhow, magnet weakened to point of magnetic effect is negligible, this does not mean that the magnet magnetic unabated