Timer in excel stops when running simultaneously

hello

hope somebody can help me with the attached file. it containes 3 timers and it should run independently of each other, meaning timer 1 should not stop even if i am working on timer 2 or timer 3.

right now, when timer 1 is paused and i start another timer then try to resume the 1st timer (while the 2nd timer is still running) a run time error will occur. I hope i explain myself clearly.. the bottomline is 1 timer should not affect the other timer whether it is running or in pause.

thanks in advance for those who can help.