FTb back door stuck: how to open it?

[h_s1]

<p>I recently acquired a Canon FTb SLR (the 'new' model, with the white line in the stop down lever). Its back door won't open. If I pull up the film rewind crank, the door does not pop up as it should. Any advice how to go about fixing this?</p>

<p>BTW, the mirror foam appears to be on its way out. Bits are stuck to its mirror and I intend to replace it soon. Could the bad foam be related to the back door problem?</p>

<p>Thanks.</p>

[awahlster]

<p>It's possible the door foam has gone sticky and is holding the door from popping open.</p>

<p>Gently try to pry the door open with your fingers while pulling up on the rewind crank. This should release it.</p>

<p>You might also try pushing the door in tighter to see if it will release. It is possible someone has already attempted to replace the foam and has a bit to much in the door channel. Also do this while holding up hard on the rewind crank.</p>

<p>If the latch has come apart (very unlikely) then you have a real pickle and will need experianced help.</p>

[h_s1]

<p>hmm. Okay, I will give prying open that door a shot.</p>

<p>Meanwhile, I have read a few forum messages using google search that suggest to freeze the camera for a few hours (in zip lock bags, e.g.) and to try open the door while cold. Foam is less sticky when cold. Any idea regarding the pros and cons of this method?</p>

<p> </p>

[paul_wheatland]

<p>Some cameras have sliding tab either at top of door or bottom of door at end of camera nearest the rewind knob. Pulling on rewind knob has no effect on unlocking the door. This may or may not be the case with the Canon FTB.</p>

[h_s1]

<p>Paul, no, there is no such tab in this camera. IIRC, FT had a tab in the bottom plate that was used to unlock the door.</p>

<p>Users with an FTb body, can you post a few macro shots of the door where it locks in the body? I want to get some idea what it looks like so that I can try something else.</p>

<p>Thanks.</p>

<p> </p>

[h_s1]

<p>Got it opened. Taking the Canon FTb's bottom plate off, one can see a triangular shape of plate in the bottom of the camera (in the front corner of the camera on the side of the film rewind knob). Pressing this plate moves the spring lock that keeps the film door in place. The plate is shown in the attached photo (see the bottom left corner of the image of the camera bottom). The plate can be pressed even by one's finger, and the camera back door pops up.</p>

<p>Next problem: I have noticed that moving the film rewind knob does not really move the spring lock mechanism. Suggestion on how to see what is wrong here?</p>

<p>Thanks.</p>

<p> </p><div></div>

[h_s1]

<p>Looks like the spring mechanism with the lock and the door latch are fine. The problem appears to be a washer that connects the rewind knob's axle with a connecting rod (which pulls the spring lock when the knob is pulled). That washer (labeled as "Knob and spring lock connection in the photo below) is not making contact with the rewind knob. I have tried to show this in the photo linked below.</p>

<p>Basically, moving the rewind knob up is supposed to move that washer up, thus pulling the connecting rod up, which in turn should pull the spring lock to pop open the film door. BTW, the gray triangular sort of the metal tab that I mentioned earlier is the exact thing that this connecting rod pulls.</p>

<p><img src="http://farm5.static.flickr.com/4013/4237865283_e7abb5fa07_o.jpg" alt="" width="640" height="480" /><br>

If somebody knows what could be the problem here, it would nice to share their views.</p>

<p>Thanks.</p>

[tomscott]

<p>Just a thought but, is it possible that the door is slightly warped causing the latch to not be properly aligned so that it is causing the release to not work? I have ran into this on some Canonets and other cameras. If so, you can usuall just grasp it with both hands and bend it slightly until it lines up properly.</p>

[h_s1]

<p>Well, got it working. The problem was solved by reseating the screw that holds the washer that connects with the knob's axle followed by lubrication of the axle of the washer. Working the knob a few times smoothed the unlocking mechanism of the film door.<br>

Looks like somebody tried to fix it without knowing much on what was going on, and probably misaligned the washer in the process.</p>

<p>Anyhow, the film door is working properly now.</p>

 

[john_shriver]

<p>If the collar on the bottom of the round shaft that should push up the triangular plate slips downward, the door won't open anymore. If someone then tries to force the door open, the latch plate will get bent and bind. If you push in on the triangular plate and it won't spring back, that's the problem. Lube won't help.<br>

To fix that, pry that end of the leatherette off the camera. Remove the two screws exposed, and you'll be able to remove the chrome latch plate. It will be obviously bent, straighten it. Reassemble, use Pliobond to reattach the leatherette.</p>