cannibal said:
WOW WOW WOW WOW WOW
finaly the counter is counting perfectly
0,1,2,3,4,5,6,7,8,9
the breadbord hole where wire of pin1 to pin12 was defected
I used another hole in the breadboard to connect pin1 to pin 12
and thats it
counting with no problems
thank you very much ljcox
also BIG thanks goes to audioguru and all other members who'ed helped me
all the best
You're welcome. I'm glad that we were able to help.
It looks like you need more experience at fault finding.
The general principles are:-
Do a visual inspection and look for bad connections, short circuits, etc. and if any joints are soldered, check for dry joints.
If that does not resolve the problem, make voltage measurements. In your case, you would have measured a different voltage on pins 1 and 12.
If pin 12 was high, you would have seen a low on pin 1. So therefore there must not be a connection between them. Note that if pin 12 was low, pin 1 would also be low and therefore you would not know that the connection was faulty. So you need to change the state of the counter to check both cases.
If you have a multimeter with a continuity function, you can check for continuity between points that are purposed to be joined. So if you put one probe on pin 1 and the other on pin 12, there would have been no continuity.
Finally, when I am building something, I check the components before I insert them. New components are rarely faulty, but if one is and you don't check it, then having to fault find when the construction is finished can waste time.