dealter checked and the result is :avr test and scan test B2960 set needs passlock cylinder replaced
it is really expensive,so i declined to change.
now the start is no problems. Is it a big problem in the future? could someone give me some advice. i am afraid some day i can not start it again.

hey i had the problem today, and it turned out the battery was going bad and didn't have enough power to turn the starter, only enough to make the click. So check that first

If there is an intermitternt open in the key cylinder, it will not start any time it sees fit.

hi,
thank you so much!
by the way i can not understand "If there is an intermitternt open in the key cylinder, it will not start any time it sees fit"
could you explain to me more detail.
thanks again