K-5 Knocking - Mirror Problem?

My Pentax K-5 has suddenly developed a fault. When I use the 2 second timer there is a rapid knocking sound. I'm assuming it's the mirror bouncing. It also shows the same fault when I initiate Live View. The image on the screen jumps in line with the knocking. If I turn the camera upright into portrait mode the knocking stops. does it sound like a mirror fault to you?

What you are probably hearing is the mirror moving up out of the way. In the case of Live View this is so the image falls on the semsor. In the case of the 2 second timer, the mirror lifts before the exposure to avoid any shake.

Thanks John
The thing is John it isn't just one knock, it continues all through the 2 second timer and also when live view is activated. It will stop (or not do it at all) if the camera is orientated into portrait mode. Giving it a 'gentle' shake usually stops it as well..

You could do with someone hearing it, it's hard to say any more without that.

Is the camera shop still there in Stafford? I wonder if they could advise you. If it's a fault though there's only one way to sort it - back for repair. JPS are the official repair house.

If you do send your camera to them, don't forget that you could join Pentax User Plus and get 20% off servicing.

In addition to what John has said, it may be a good idea to film the knocking without a lens attached (be careful of dust in the environment). There's a possibility that something is stopping the aperture mechanism from moving freely (and this causes the mirror to flop).

Another thought. When using Live View the image on the screen is jumping up and down in line with the knocking sound. Could it be the sensor and not the mirror?