D200 & 300 focus issue

[lisa h]

Hi, I had a focus issue a few time with my D2oo but figured that it was specific

to that camera. Recently I have had the same issue w/ my D300. Basically, the

camera will sometimes stop auto-focusing; the red boxes won't light up & the

focus beep won't sound. When this has happened I check over all my settings

(make sure that the 'S' hasn't switched to 'C' mode) and I turn the camera off &

back on, plus remove the battery, but nothing seems to help except for waiting a

little while. When it most recently happened though, I took off the lens and

put on a different one & then everything worked fine. I then switched back to

the other lens & it was still working fine so I know that it wasn't an issue

with that first lens.

 

Any thoughts/ experiences on this?

 

Thanks,

Lisa

[michael_darnton1]

Have you tried wiping off the electrical contacts on the back of the lens and inside the camera's lens mount?

[lex_jenkins]

Be very careful with approaches to wiping contacts. If done improperly and the contacts are damaged it may invalidate your warranty.

 

Which lenses are you using?

[ShunCheung]

It sounds like the electronic contacts around the lens mount may be oxidized.

 

We have had a number of threads on cleaning those contacts. A lot of people use a Q tip with alcohol. It is not a good idea to use a pencil eraser. If you search in this forum, you should find a lot of discussions, but the following one is informative:

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Ouxs

 

In particular, see the suggestion by Joseph Wisniewski.

[lisa h]

Hi, yes based on my last experience it sounds like something to do with either the camera or lens contacts. Weird that it has happened with different bodies & lenses though. The recent experience was with the Nikkor 85 1.8 before I changed to the 17-55 2.8.

 

I'll check out that link.

 

Thank you.

[lisa h]

I have had all of my lenses (& the bodies & flash heads) checked out by a Nikon Authorized Repair Center recently. The 17-55 had to be sent for repair but they said that everything else, including the 85 1.8 was fine! They did clean the 85 inside & out and when I had the issue recently it was my first time using the lens since it was cleaned. It must be the contacts on the body.

 

I had an issue a few weeks ago with the auto-focus assist beam on my SB-800 not working properly for a little while, then later in the night it was fine. Maybe that stems from the same (contact) issue...?

[ShunCheung]

Lisa, please keep in mind that you need to clean the contacts on both sides, i.e. on the camera body as well as those spring-loaded contacts on the lens.

[lisa h]

Thanks everyone! I think I am going to get some 'Deoxit' to clean all of the contacts

(after doing a search on cleaning contacts I found this interesting thread regarding

Deoxit :

http://forums.dpreview.com/forums/read.asp?forum=1039&message=26374611 )