u/Akron-brn69

Better pic of control board

Need to know if I can hook up the blue wire to the b/c even though there is a wire there already

Hello, trying to set up Nest because older thermostat didn’t have smart functions. My furnace and A/C are only a couple of years old.
When I hooked up the nest, I didn’t use the blue common wire because the old one didn’t use it.
Nest said it didn’t have any power, so I stopped the blue wire and inserted it into the nest but it still says it’s not getting power.

Went down to look at the control board on the furnace and there is a wire hooked up to the C terminal, but it’s not blue.

Not sure what to do. Any help is appreciated. Here are pics. Thanks!