My flash is not being recognized by my D7100 anymore. I have reset the camera settings to default and reset the flash. I have removed the batteries while the unit is on. I have replaced the batteries. The flash fires from the test button. At times is will fire from the camera but rarely. I have wiped the contacts and reseated the flash in the shoe.
When in AUTO the onboard flash tries to pop up. In A the meter acts like there is no flash - and it does not flash. The pop up flash works fine.
I can test fire all day - the device seems good but the communication to it seems to be the issue - or settings somewhere.
New wrinkle - I tried an off brand flash (that I can also test fire) and it is doing the same thing. I am concerned this is moving to a camera issue not a flash. Has anyone seen a camera problem where it does not recognize the external flash? I'm using a newer D7100 - was working previously.
There are three possible issues: 1. Oxidized electrical contacts on the Cameras hotshoe.
Clean the electrical contacts with DeOxit.
2. The cameras hot shoe slides have opened up preventing the electrical contacts on the flash from making good contact with the camera.
How much play is there between the flash and the hotshoe? Is there a snug fit or does the flash wobble a little before you lock it in? You could try pushing down on the flash while you release the shutter and see if it works. Just keep the pressure vertical and don't over do it.
3. There are one or more bad connections or a bad circuit board inside the camera body.