Pin 6 is inhibit, needs to be low to get I/O from the switch (4051) Pin 7 connects to the most negative voltage Vee used (Bi-Polar supplies) and pin 8 is Ground Vss these pins must be pulled down (6) and 7 and 8 are usually grounded Pin 7 Must be Connected. From my experience several years ago... and the data sheet. To remember why mine didn't work the first time...
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