Problem with the HEF4008BP IC chip ??
i just bought a HEF4008BP 4 bit binary adder ic. I connected pin 16 to V+ and pin 8 and 9(Carry in pin ) to ground and then set up a 8 way DIL switch with 10k and 1k pull down resistors to gnd and the switch to the inputs of the adder.Then i connected the outputs of the adder to the positive of a 3mm led each separately .The dil switches are all of but still all the led's light up once i connect the 9v battery . The chip can run off 5v-15v . Also there is no sign, name or logo of a manufacturer on the ic .Is this a fake ic or might i have possibly blown it or have i done something wrong .Please help me.