5d Mk2 Auto Focus Pins

I have a 5D Mk2 on loan from a friend and after only 23 shots, the auto focus has failed. I've checked all the usual things, AF switch, battery power, camera settings and no joy.

Then I had a look at the auto focus connector pins. It would appear that the three pins have somehow become pressed down just above the level of the plastic surround and when the lens is on, there must be no contact between the contacts.

Has anyone ever come across this before? Or does anyone know how much a repair would cost?

Sods law really as I've been shooting Canon gear for almost 20 years and never come across this issue until I borrow someone elses pride and joy...!!

Never heard of this problem on Canon Cameras, but I have seen something similar on other types of electrical contacts. Try a piece of soft materiel, such as plastic, and GENTLY push the contact in a few times - it will probably free up after one or two tries. The contacts have probably got a bit gummed up, in the long run they will probably need to be cleaned/lubricated - I wouldn't attempt that myself.

Ah,I tried that with a plastic golf tee, no joy. They move up and down and do not appear seized and there's no gunk or grime, camer is spotless.

It's as though the pins are stuck down and need to be pulled back up. I've attached a pic to show as it's easier than explaining any more!

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Had a look at my 5DMKII and you are correct, those pins should be extended. Don't know what to suggest, just thought you might like confirmation.

If you hold the camera with the lens opening pointing down, do the pins extend? If so, it could be that the returning spring (if there is one) has broken. If they don't extend then they could be gummed up as previously suggested.

No, the pins don't drop when the camera is inverted. I've tried everything I can bar opening it up, which I won't do myself! It's off to the shop tomorrow to get looked at and no doubt I'll have a decent repair bill when it comes back! Luckily, my friend who lent me the camera is very under standing!!

Thanks again.

That's odd...

Those pins each have their own return spring, it would be highly unlikely that all three would fail at the same time.

Best guess, something sticky got onto those pins and is keeping them from springing back out into position. Grease or oil, thickened and dried out from age, might do it too. I carefully checked on my camera and there is a light spring action returning each spring individually to position.

A repair shop should be able to fix it relatively easily and inexpensively. If it were me, I'd try using an electronic contact cleaner and lubricant (here in the US Radio Shack sells one in a spray). That would have to be done very, very carefully to keep off the mirror, shutter, etc. With an aerosol spray, I'd squirt some in the cap, then pick up a drop with a syringe or even a toothpick, and put just a little on the pin. Usually that cleans things well enough that the spring will return the pin to position all on it's own.

Further to my previous post I just noticed that there is a rough groove in the plastic either side and between the pins. I don't have a 5D2 but have just checked my collection of 5 EOS film bodies and two digitals and none of them have this groove. It looks like damage caused when mounting/dismounting the lens. I don't see how a Canon lens could cause this, due to their contact design but that is what it looks like to me. Perhaps another 5D2 user could check for you?

I'v repaired that problem afew times on various models, Normally I say give it a go but this particular repair I wouldnt wish on anyone, it it DIFFICULT, I could have got the part and replaced the whole unit but it takes afew weeks from america and people need it done faster than that.

Just checked mine - no groove

I'm guessing the groove (and probably the damage) would be from an adapted lens with one of the aperture pin/tab things. Just a guess, but I cannot think of what else would do that.

send it in to canon for repair

Ah, the results are in!!

I had the body in the shop today and it turns out that the groove is indeed damage caused by the lense. The lense I borrowed with the camera (16-35mm f2.8) had lost it's retaining screw that stops the lens twisting on too far. As this was missing, at some point, the lens has been put on and the secondary spring loaded retaining pin on the mounting ring has failed to stop the lens going too far.

As a result, the borrowed lense has been twisted on, no retaining screw has meant the lense has gone on too far and the secondary retaining pin has not managed to stop it. As the lense has twisted round, the second set of (raised) contacts has run over the pins, forcing them back into the body.

The shop are sending the body & lense off to an independant repair specialist who will replace the missing retaining screw and also have a look to see if the contact pins can be repaired or replaced. Aparently, this is not an unusual repair, but unusual to have this set of circumstances.

Many thanks to all who had a go at the diagnosis, a learning curve all round I think! I've been using Eos lenses for 20 years and never knew they had a retaining screw, think I will be checking all mine now!!

since it was your friends "fault", is he gonna help with the payment?> seems only fair.

1st time I'v heard of it, though I'v seen individual pins stuck quite afew times, let us know what prices you are quoted. I would say £80ish for a repair or £100ish for a replace.