My D80 won't work with my SB-600 hooked up?

[JohnS.]

My SB-600 is only like a year old, fresh batteries in it. I was just using it with my D80 earlier today! Now when I hook it up to my D80, on the top display, the flash icon blinks and the D80 refuses to take a picture with the SB-600 hooked up. Yes it's locked, yes it's on TTL, the camera will focus and act as if I'm about to take a picture but it won't take a picture after it focuses. The D80 has 2/5 battery bars left. Could that be why? The SB-600 will test fire, I've tried resetting both the camera and the SB-600. The SB-600 works on commander mode but not TTL.

I'm absolutely stumped.... Nothing is working. Help?

edit - Well I called Nikon support this morning, they couldn't do anything. I took it back to where I bought it from and the guy hooked up an SB-700 and it worked on TTL. So he looked up my info and guess how much time I had left on my 1-year warranty on it? 1 day...sweet! So I left it with them to get it sent back to Nikon. Unfortunately, they said it will take up to 6-8 weeks at this time of year. I picked a bad time.

 

[KmH]

Yes, the low D80 battery could be the issue. It takes a fair amount of power to fully charge the SB-600's flash capacitor.

The SB-600 may be manually test firing at much less than full power.

 

[JohnS.]

I just fully charged the battery and it's the same thing. The flash icon on the top display keeps flashing and the camera won't take a picture with the SB-600 hooked up but will manually fire and work off the camera on commander mode.

 

[JohnS.]

Actually, the D80 will take a picture with the SB-600 hooked up, as long as it's not turned on. But the second I turn it on, the flash icon on the top display starts blinking and it won't take a picture.

Another update. If I hit mode to have it display "(M) 1/1", it will take a picture with the flash, but on regular TTL, it won't. I don't get it. The camera is set on TTL....

If it makes a difference, usually on the SB-600 display, isn't it supposed to say like "BK" on the right of TTL and something on the left when shooting hooked up to the camera? It doesn't right now.

I consulted the D80 manual and it says if both are blinking, "Optional Speedlight that does not support i-TTL set to TTL mode.". Well I've been using my SB-600 with this D80 since I got it almost a week ago.... Solution says, "Change flash control mode for optional Speedlight." and references pages 120 and 141. I checked and all my settings should be right... My "Built-in flash" (number 22 on pencil icon) is set to TTL.

Any ideas?