Circuit to test ICs at home? (74hc04, 74hc08, 74hc32)
7400 series ICs take a bit of getting used to, as they are not as straightforward as, for instance, 74HC00 types.

Here are circuits to use with, for instance, the 7404 and 7400.




You'll note that the input switches provide a LOW input when closed, and the output LEDs are ON when the output is LOW. If this gives you too much trouble mentally, use unused inverters to switch the input and output polarities. But keep the switch and LED connections as they are.

TTL inputs are best driven by pulling them down or letting them be pulled up with a (obvious name, here) pullup resistor. usually in the range of 1k to 10k. And TTL outputs are much better at sinking current rather than sourcing it, so don't try to drive an LED output to ground.