Who are we?  Featured Cameras  Articles  Instruction Manuals  Repair Manuals  The Classic Camera Repair Forum  Books  View/Sign Guestbook

Pentax spotmatic mirror locks up Log in | Log Out | Topics | Search
Moderators | Register | Edit Profile

Classic Camera Repair » Archives-2005 » Pentax spotmatic mirror locks up « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

John Meyers

Rating: N/A
Votes: 0 (Vote!)

Posted on Tuesday, February 01, 2005 - 03:24 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I just purchased an old Spotmatic. When the shutter speed is set at 1/500 or 1/1000 and then released, everything works fine. But if the camera is set at 1/250 or slower, the shutter fires, but the mirror stays up. It will only come down if the shutter speed is then set at 1/500 or 1/1000 and the shutter released again. When the mirror is locked up, the shutter continues to work properly at all speeds.
Is this an easy fix for a novice like me?
Thanks.

John Meyers
Top of pagePrevious messageNext messageBottom of page Link to this message

Ed

Rating: N/A
Votes: 0 (Vote!)

Posted on Tuesday, February 01, 2005 - 03:54 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

It sopunds like the curtain is set too weak. Open the back and with the shutter tripped, reach under mirror with a finger with the same finger and thumb, gently grasp the curtain and lightly pull it toward the wind lever end of camera. There should be sufficient tension so that the curtain will return when you release it--without needing pushing, but not too much spring tension. If it does to want to return positively, then the curtain tension setting needs to be increased. If you find this to be the case, I can tell a procedure to do it.
Top of pagePrevious messageNext messageBottom of page Link to this message

John Meyers

Rating: N/A
Votes: 0 (Vote!)

Posted on Wednesday, February 02, 2005 - 07:16 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I did as you suggested, and the curtain returns to it's starting position when released. There was plenty of spring tension on it. But as I said in the original post, the problem is not the shutter curtains, it is the mirror. Even when the mirror stays in the up position, the shutter continues to operate properly. Why does the mirror stay up?
Top of pagePrevious messageNext messageBottom of page Link to this message

Ed

Rating: N/A
Votes: 0 (Vote!)

Posted on Wednesday, February 02, 2005 - 09:10 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

When the shutter trips (the second curtain) it releases the mirror so it comes back down--weak shutter tension will make it not return properly. The other possibility is the mirror shock foam at the top where mirror comes to rest--it gets gummy. This is not usually a problem with that model, as the amount of foam there is little. You can test this by gently pulling down on the mirror after you trip the shutter. If you look at the bottom, with cover off, you'll see a gear wilth a pin that rotates and the pin hits a lever that releases the mirror.
Top of pagePrevious messageNext messageBottom of page Link to this message

Dan Mitchell

Rating: N/A
Votes: 0 (Vote!)

Posted on Wednesday, February 02, 2005 - 10:45 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

On the bottom you see a gear that is driven by the closing curtain. This gear has a stud on it that trips the mirror return. If the shutter is slightly slow the gear is not driven with enough force to release the latch. Sometimes cleaning the gear and also the ends of the curtain rollers will help.
Top of pagePrevious messageNext messageBottom of page Link to this message

John Meyers

Rating: N/A
Votes: 0 (Vote!)

Posted on Thursday, February 03, 2005 - 07:40 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I can say that the mirror foam is in great shape. Not gummy at all. When the mirror is stuck in the up position, I can pull it downward very slightly, maybe a millimeter or so, and then it stops. It is certainly not being held up by sticky foam.

So my next step would be to remove the bottom plate and look for the gear you both are referring to? (I am new at this, so please bear with me). Then I should try cleaning it first perhaps. What should I use to clean it?

John Meyers

Add Your Message Here
Post:
Bold text Italics Underline Create a hyperlink Insert a clipart image

Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action:

Topics | Last Day | Last Week | Tree View | Search | User List | Help/Instructions | Program Credits Administration