Speedlite not flashing

[SAWYER]

I have a 430ex that will not flash. It powers up and seems normal except it will not fire. The pilot light on the back is solid red and on the front side there is a solid red light as well. I have tried brand new batteries with no luck

 

[randomrogue]

Another set of batteries and a trip to a local camera shop?

 

[SecurityTheatre]

I assume you tried to press the test flash button.

If that does not work AND it's not working when mounted, it's probably toast and would need repair/replacement. There are several high voltage capacitors that could go out, and the flash bulb itself can go bad.

If the test button works, but it still won't fire on a camera, it's a problem with the connection on the hotshoe somehow... that's different, but still usually requires repair (unless you can just clean up the connector)

 

[SAWYER]

It will not fire off the camera either