Hi Chris,

maybe, Richard point in the right direction and you use the wrong display. Please watch, that common cathode and also common anode displays usual.

The 7447 outputs drive low level for using only a common anode display.

You can test it with connecting its outputs with ground. If the display leave still dark, than it was the wrong type.

Also watch, that current limiting resistors (e.g. 100R) must be in series to the display segments and the common anode was connected to VCC.


Peter