What is cause of internal flash on 60D not functioning?

[digital]

Could be several things.  Is flash firing enabled? Next you are askking about internal so I'm assuming you are talking about the pop up flash. Is it up? If exernal do you have a hot shoe flash moutend on the camera?  

[Maxcollectsit]

External flash works, when trying to use internal flash menu states external flash is connected.

[JohnfromPA]

There is a small micro switch in the hotshoe that occasionally sticks, making the camera think an external flash is mounted.  As you look at the back of the camera, the switch is on the right side rail I think  about 1/3 from the front.  Get a tooth pick or very small screwdriver and move it around so it pops up.

[Webbishy]

Thanks, John.

I was going crazy trying to figure out what the heck was going on with this 60D body. Actually, I couldn't see the microswitch on the hotshoe rail, but by "flicking" the spring strip inside the rail with a toothpick, I was able to get the camera to stop saying there was an external flash attached.

Thanks for your post.

Al G.

[brothers]

The recommended correction worked. There must have been a piece of debris or something. I used a very thin kitchen knife and slid it under the metal shoe mechanisms on each side of the boot. 

[AlexKwakIT]

Thanks, you saved my day!