Mamiya 645 1000s Mirror Lockup Issue and Metered Prism Problem

[Mistermike]

I just recently picked up this little beast of a camera last week and I'm having a couple issues I can't figure out.

#1: The mirror locks up when I'm using a shutter speed of 1/250 via the the shutter speed dial on the camera body. Every other speed setting works fine and the mirror functions properly. I've opened the back door to see if the shutter curtain opens and closes when using 1/250, and it does. However, the mirror continues to stay locked up. The only way to drop it down is to advance the winder in which it does advance the film like normal. I'm using a brand new battery and have checked the contacts which are clean as a whistle. Even if it were the battery, I would be able to press the red battery check button to drop it down, but this is not the case. It's as if it were designed this way, but I doubt that.

#2: I have a metered prism with a shutter speed dial on top. So when you turn the body shutter dial to the red dot, the prism shutter dial should now take over. However, It does not change any speed it's set to and instead locks the mirror up and the shutter curtain stays open. Now in this case, the only way to drop the mirror down and close the curtain is to press the red battery check button. I've tried every single speed on the prism shutter dial and all is the same. The interesting part is that the meter works fine and when checking the battery, the green light comes on strong.

Has anyone come across these problems or does someone know what the issue may be?

I've done tons of searching and couldn't find any solutions. But i'm excited to be apart of this community so I look forward to any help and discussions!

Thanks

 

[shutterfinger]

Here is a link to your camera's instruction manual. http://www.cameramanuals.org/mamiya_pdf/mamiya_m_645_1000s.pdf
1. take the battery out.
2.remove the finder.
3.inspect all electrical contacts. they should be the same height on both the body and finder. they should be bright brass, if dull clean with a pencil eraser or metal polish without bendig them.
4.battery test buttons only tell you if there is a battery with some power in it installed. the battery test does not put the battery under operation load and therefore may fail under load but show good with the test button. If the test button shows it bad then it is.
5.if all this is good then it may be time for a trip to the repair shop.

 

[Anthonyl182]

Have you found a fix for your problem, I just bought a mamiya 645 1000s and the same thing happens when I shoot at 1000 and 500 shutter speed, every other shutter speed is fine, I’ve looked everywhere and haven’t found a fix for it.

 

[bunktheory65]

I have a 1000s and i have noticed that the mirror has a "hang" when fired via the prism shutter control unit.
NORMALLY when
1. the camera is tipped upwards at all
2. the meter is still active and LEDs are glowing.

PERSONALLY i think its either a voltage drain on the shutter circuit when using the meter shutter speed control or an issue with a return spring on the mirror itself having lost strength over age. Possibly even a lube issue.

Just use the built in meter to figure out the exposure settings, and switch the main shutter control to that shutter speed and see what happens