Apple Wireless Keyboard Unknown problem

Hello,

i have a very weird problem. i was using apple wireless kb for a year without problem but today it stopped working.when i click power button the light starts to blink fastly without a pause (blink-blink-blink-blink) not like (blink-blink-pause) i replaced the batteries i took batteries off and put new batteries no difference.

i searched internet so far but couldnt find the problem.

any ideas ?

thanks