Canon EOS 3 bc issue and mirror halfway

[brupsilva]

Hi, everyone. I recently bought a Canon EOS 3 with this BC problem. When I fire it the mirror goes and stuck halfway and the BC message appears. When I fire it again it release the mirror.
I already cleaned up the contacts and hit the mirror's magnet region.
Any ideas?

 

[Mike Sowsun]

Most of these BC errors result in the shutter not firing at all, and no mirror movement. I call this a “sticking shutter magnet”. This can often be fixed with by either tapping the magnet, or putting a strong magnet near it.

It sounds you have a more serious problem with yours.

 

[brupsilva]

Most of these BC errors result in the shutter not firing at all, and no mirror movement. I call this a “sticking shutter magnet”. This can often be fixed with by either tapping the magnet, or putting a strong magnet near it.

It sounds you have a more serious problem with yours.

I don't know. I found this video where I can't see the mirror but the "sound" is exactly the same. I suppose its happening the same with these guy. I need to find a strong magnet to test it.

 

[brupsilva]

I recorded this video from my camera now:

 

[Mike Sowsun]

That sounded like the shutter fired when the mirror went down. I would check the Custom Functions to make sure Mirror Lockup is off. But even if it is enabled, there shouldn’t be a BC error.

 

[brupsilva]

That sounded like the shutter fired when the mirror went down. I would check the Custom Functions to make sure Mirror Lockup is off. But even if it is enabled, there shouldn’t be a BC error.

View attachment 360198

I did check. It's 0. I did a clear CF too to restore as factory. But... nothing happens. ((

 

[koraks]

Welcome to Photrio, @brupsilva !
Sorry to hear about the issue with your EOS3. The first thing that comes to mind is a problem with its power supply. The obvious thing to check if a fresh battery or a different brand of battery produced the same problem. If so, then there might be a problem with aging capacitors, resulting in a brownout condition during the shutter sequence.

 

[brupsilva]

Welcome to Photrio, @brupsilva !
Sorry to hear about the issue with your EOS3. The first thing that comes to mind is a problem with its power supply. The obvious thing to check if a fresh battery or a different brand of battery produced the same problem. If so, then there might be a problem with aging capacitors, resulting in a brownout condition during the shutter sequence.

I'll try to clean even better the battery grip contacts and use brand new AA batteries. But this batteries I'm using was in my EOS 1N RS that was firing normaly. If the problem is in the electronics (capacitors) there are some hope or not?

 

[koraks]

Let's hope the batteries make a difference, but I agree that it would be odd that they work fine in one camera and not in another. However, stranger things have happened!

If the problem is in the electronics (capacitors) there are some hope or not?

Sort of; firstly, it's a bit of an educated guess on my end, so no guarantees that this is really the problem. And even if it is, the bad news is that it'll be far more difficult to resolve than on the far more simple cameras that are often associated with capacitor problems. These EOS cameras are highly integrated and the electronics are very complex. This means that identification of potentially bad capacitors is already a major challenge, as well as the disassembly involved in it.

All considered, if the batteries don't help, things will likely get very complicated, very quickly.

 

[brupsilva]

Let's hope the batteries make a difference, but I agree that it would be odd that they work fine in one camera and not in another. However, stranger things have happened!



Sort of; firstly, it's a bit of an educated guess on my end, so no guarantees that this is really the problem. And even if it is, the bad news is that it'll be far more difficult to resolve than on the far more simple cameras that are often associated with capacitor problems. These EOS cameras are highly integrated and the electronics are very complex. This means that identification of potentially bad capacitors is already a major challenge, as well as the disassembly involved in it.

All considered, if the batteries don't help, things will likely get very complicated, very quickly.

I still have hope in the magnets or, something in the mirror box.. like a crank or something.

 

[koraks]

Anything is possible at this point. In any case, I hope you can resolve the issue!

 

[Laurent]

Mine developped such symptômes, and that's why I decided to sell it, out of the fear it would brick as my t90.

In my case, only higher shutter speed were affected, 1/2000 and above IIRC.

 

[Mike Sowsun]

Check out this YouTube video that shows how to access Error Codes: Checking Error codes on EOS 1

 

[brupsilva]

Check out this YouTube video that shows how to access Error Codes: Checking Error codes on EOS 1



View attachment 360503 View attachment 360504

Mine was getting BC error number 16. So I cleaned de Custom Functions. Now its getting error number 11. But nothing changes. I think its different from EOS 3 to EOS 1V.