Nikon D80, how do you turn off the r09, r11 and/or r17 alert (depending which Image Quality setting I have the camera set to)? I have sent the camera back to Nikon twice and twice it has come back with the r-whatever still appearing on the LCD screen once I depress the shutter button.

"r11" is the estimated remaining (r) exposures on the memory card. No error msg, just information for the user.

Both items can be found in the D80 manual.The r09 is found on page 36 lower. It is the number of shots the buffer can handle. The Err is not a good thing. Turn off the camera, remove the battery then replace it, turn on the camera reset to factory bottom of page 129.

Try resetting all features back to default to see if that will clear it up. Your manual will have these instructions.
otherwise you can check out this repair https://www.teleplancamerarepair.com/quote/cart.asp?iProbID=33&mo=96
error codes are quite common in most cameras and they all have different meaning. this is a great camera by the way.

Glad to be of help :-)

nikon r09,r11, etc . it mean memory buffer of your camera. memory buffer is a temporary memory for your captured images before it store to memory card.
if r00 it mean, you can't take a picture, even 1 picture... that because the camera buffer memory is full.
the number of memory buffer will also drop if noise reduction on

I belive this isn't a fault but more to do with how you are using the camera. The r09 message is to do with the camera buffer and how many more pictures it can hold. You do have a memory card installed, right? The r09 is normally not an error, but simply an indicator of how many more pictures you can take in the current burst before the buffer fills. The number will vary according to the image quality and size settings.

Try cleaning the lens contacts with alcohol or sprit

Try this.

Switch D80 on.
Reset the camera by pressing the two buttons with a green dot beneath them on the top of the D80, right hand side.
The buttons are AF and +-.
These must be pressed together at the same time for a few seconds.
This is just in case you have set something strange, you do not need to do this all the time.

Set the command dial to Auto.
Set the button on the lower front/left hand side to AF.
Set the lens to A.

Now you can just take pictures, the D80 will autofocus and set the exposure itself.

First, the r09 refers to the amount of memory buffer photo storage is available. That's to say that 9 photos can be stored in the memory buffer, while the latest pictures are being written to the slow camera card. It's bursting 9 photos. Depending on your image quality and type, this will be a different number.

Second, make sure you are in the P or Auto mode while testing, or clarify what mode and settings you have. A picture won't take on my D300 if my lighting is too low for my current settings.

The r codes just indicate that you have that many shots in the image buffer. It is not an error indication.  Depending on the mode, the camera either will or will not allow you to take the shot when the image is out of focus.  Make sure the lens is set to A for auto, and try to focus on something outside in good light with lots of detail.  It sounds just like you aren't actually getting a good focus lock.