Originally posted by AfterPentax Mark II I think the fault lies with the K-3 III, not with the Metz flash. If it still works well with K-5 than it must be something in the camera that is not working as it should. As your camera is still under warranty I would put the problem to the seller of the camera. The importer Transcontinenta can do nothing for you, as Metz is out of business. You will have more success with claiming your warranty from Ricoh.
I didn't mean Transcontinenta as the importer, but Ricoh indeed.
But I found the solution, and it is something stupid (as I feared).....
Triggered by the comments of Kwong and Tjompen that their flashes do work, I realised that after I updated the camera's FW I left the shutter in the setting Electronic Release. That's the problem, and the solution is easy.
Thanks again everyone, for your comments.