Attaching lens shuts 7D down

[GBHajim]

Aloha!

I have a Canon 7D. It won't turn on with a lens attached.

The body alone turns on fine, but when attaching the lens, it shuts down.

It isn't the lens because I tested it on a 5D with no problem.

Ideas? I cleaned the contacts with alcohol, but it didn't change anything.

I'm going to update the firmware, but I'm really at loss at what to do next.

Help!

[Waddizzle]

Okay, there are a couple of recommended guidelines for attaching and detaching lenses.  If you're anything like me, you almost never follow them when you're "in the flow", so to speak.

1.  Always have camera powered off when attaching and detaching lenses.

2.  Always have all lens switches set ot their inactive position: i.e. IS turned off; AF/MF set to AF.

3.  Turn the camera on before you turn on the lens, and turn off lens before turning off the camera.

Okay, try that stuff to see if it makes any difference, and try a different lens if you have one available, too.

[GBHajim]

Mahalo for the suggestions. Tried to no avail.

[Waddizzle]

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@GBHajim wrote:

Mahalo for the suggestions. Tried to no avail.

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Okay, what exactly happened for each scenario?  Also, you might try removing the battery for half a minute or so,. And, then retrying everything that you've tried so far.

If no one has had you try resetting the camera, then try that, too.  However, it does sound like you have more of a mechanical problem with the lens connection itself, as suggested to you to check the actual electrical connections to the lens. 

[GBHajim]

The first time? I put in the battery. Turned on the camera and got an Error 20. I reseated the lens and the camera turned off.

After that no more Error 20 because the camera won't even turn on with the lens attached. When I take off the lens, the camera will come on. If I turn it on without a lens, it functions fine, but the moment the lens clicks into place the camera shuts down.

Tested it with two Canon lenses and these both work fine on a 5D.

I cleaned the contacts with alcohol and checked the 'springiness' to no avail.

Resetting the camera? You mean taking the battery out and turning it on? Or is there some other reset?

[GBHajim]

BTW I really appreciate your help!

[Waddizzle]

That's odd.  It shuts down when the lens "clicks into place" and locks, but not before.  Yes, that is when the contacts between the lens and camera come into contact with each other, but still. ...  ....that's odd to me.  It definitely sounds like a mechanical problem with the electrical connections and contacts.  But, you say you checked them.

As far as "reset" goes, there should be a menu setting called "Restore Factory Defaults" or something like that.  Be aware that executing it is irreversible.  Any custom settings and data in your  camera's memory will be lost.  You will even have to re-enter the date and time again, just like it was new out of the box.

[GBHajim]

Reset. No change. I guess I ship it to Canon?

[Waddizzle]

Yup, time for a visit to the repair shop.

[TCampbell]

Each of the contacts on the "lens" side is a contact plate.  But each of the contacts on the camera body side is a springy "pin".

Gently push in on each pin and make sure they can each spring back out equally well.  I'm wondering if some debris is jamming one of your pins and it isn't really making contact.

Also, the gold plating on the contacts is very thin.  Be careful when cleaning and do not use anything abrassive (a soft cloth would suffice).  Canon even points out that a pencil eraser is abrassive enough to remove the gold plating.

Do you have a different lens that you can test with this particular body? 

Also... is the lens that causes the camera to shut down a Canon brand lens or a 3rd party lens?