Rainer
thanks,
i did think maybe there is hardware issue with counter, but, it counts fine up to 8 . then re-cycles ( 1 to 8 again and so on ).
unless i am missing something fundamental about the IC, way it works.
have had someone say to me about 24v to the mux, but again, if there was a supply voltage issue, then surely , it would over heat, and break down,
there is no physical sign of rise in temperature on either IC.
i am stumped, oscilloscope shows clock out of 555 timer is consistent. I will scope the output from the counter again tomorrow