I made a counter using this design and it works fine.

and now Im planning to make a reset button for it but I don't know how to do it. I already looked at the j-k flip flop datasheet and read its truth table then tried changing the J or K input to "0" but it didnt reset.
Need help here. ( ;

 

Pins 3 and 8 of the 7476 are clear pins activated on LOW. They work asynchronously. Try them out.

 

I tried but it only pause the counting.
should I do it on all 7476 IC's?

 

nvm...
thanks for the help great man Geo. ( ;

 

Yes, as I guess you found out, you must reset all 4 JK-FFs simultaneously for the counter to return to 0.