Wiring Schematic for 8 digit seven segment (7.2 volt) display

[deronbutler]

@TomGeorge

@TomGeorge

What are you using as a power supply?

I'm using Arcity 5V 12V 24V Output Switching power supply found
here

@TomGeorge

Have you measured the 12V supply while displaying 3's or 8's or 1's ?

a steady 11.8 volts at the power supply

@TomGeorge

Have you got the gnd of the 12V supply connected to the gnd of the Mega?

Yes