645z Shutter sometimes does not fire

Dave645 · 09-26-2017, 12:39 AM

The shutter on my 645z will sometimes not fire when I press the shutter button or when I go into live view. Has anyone else encountered this issue? As far as I can tell, it seems to be a software issue and not a problem with the hardware.

To be clear, the rest of the camera behaves as if an image is being taken. The mirror goes and the sensor takes an all black image, and saves it to the card. The camera is responding, but the shutter itself does not fire. I can seem to reset the camera in one of two ways. First, if I take off the lens and put into live view, the mirror goes up, but no shutter. I repeat, and the next time the shutter goes up and normal live view operation ensues. Or, when in live view, I can operate the depth of field preview button twice, and the camera will return to normal operation

I am running the latest firmware, 1.30. I have been trying to reinstall the firmware manually but cannot get the camera to recognize an SD card with the 1.30 binary file on it. Has anyone else managed to reinstall the same firmware version?

Thanks, David

D1N0 · 09-26-2017, 01:40 AM

Sounds like to a shutter starting to fail to me.

postnobills · 09-26-2017, 04:03 PM

Start out with a camera reset. Wrench Icon > 3 > bottom line.
Then navigate to C > 5 > Reset Custom Functions.

When doing a firmware update the SD card is only recognized in Slot 1.

Make sure you have a fully charged battery.
Try a different card.

Then get back to us.

Dave645 · 09-27-2017, 01:29 PM

Thanks for the ideas. Resetting the camera to factory settings does not fix the issue. I am fairly certain that the shutter mechanism itself is just fine. Everything works perfectly when I have a D-FA lens attached to the camera.

I cannot seem to reinstall the firmware. I am using a formatted SD card with the binary file in the root directory, in slot 1, with a full battery. My only guess is that the update procedure only works if there is an older version of the firmware on the camera, but I have not gotten confirmation on this.

I can now reproduce the problem in a deterministic way, and it appears to be related to the aperture closing mechanism. If the aperture lever in the camera does not move (i.e., the lens is set wide open) then the camera will take one frame properly. On subsequent frames though, the shutter will not open. Allowing the aperture lever to move again, either by stopping the lens down, or removing it from the camera and then taking some frames will reset the camera to normal operation. This happens will all of the older lenses I have tried that have the aperture mechanism controlled by the camera. When using a modern D-FA lens, the shutter never fails to fire. So, I have narrowed it down to something funky happening with the mechanical aperture mechanism that then for reasons I cannot fathom, affects the shutter. The practical effect right now is that I cannot use older A and FA lenses wide open.

**iCrop** · 09-28-2017, 07:24 AM

Originally posted by Dave645

I can now reproduce the problem in a deterministic way, and it appears to be related to the aperture closing mechanism. If the aperture lever in the camera does not move (i.e., the lens is set wide open) then the camera will take one frame properly. On subsequent frames though, the shutter will not open. Allowing the aperture lever to move again, either by stopping the lens down, or removing it from the camera and then taking some frames will reset the camera to normal operation. This happens will all of the older lenses I have tried that have the aperture mechanism controlled by the camera. When using a modern D-FA lens, the shutter never fails to fire. So, I have narrowed it down to something funky happening with the mechanical aperture mechanism that then for reasons I cannot fathom, affects the shutter. The practical effect right now is that I cannot use older A and FA lenses wide open.

Does the shutter operate properly if the lens aperture ring is in the 'A' position? If so, you should be able to shoot wide open using the aperture control on the camera. Good luck.

Dave645 · 09-28-2017, 02:00 PM

Yes! Great suggestion, thank you. The camera operates 100% normally when I set the aperture ring on the lens to "A" and then set the aperture electronically through the camera. I still don't understand the root cause, but clearly the camera is happy when the body has control over the aperture position. Being new to the Pentax system, I had not realized that I could set the aperture on an FA or A lens via the camera. Coming from a Canon system, I had enjoyed the nostalgia of a lens mounted aperture ring, but I honestly find adjustment from the camera dials more convenient. Again, thanks for this note. Camera is effectively 100% functional if I just leave all my lenses on "A"

**iCrop** · 09-29-2017, 07:12 AM

Originally posted by Dave645

Yes! Great suggestion, thank you. The camera operates 100% normally when I set the aperture ring on the lens to "A" and then set the aperture electronically through the camera. I still don't understand the root cause, but clearly the camera is happy when the body has control over the aperture position. Being new to the Pentax system, I had not realized that I could set the aperture on an FA or A lens via the camera. Coming from a Canon system, I had enjoyed the nostalgia of a lens mounted aperture ring, but I honestly find adjustment from the camera dials more convenient. Again, thanks for this note. Camera is effectively 100% functional if I just leave all my lenses on "A"

Glad to help. That's what this forum is for.

texandrews · 09-29-2017, 01:08 PM

Originally posted by Dave645

Yes! Great suggestion, thank you. The camera operates 100% normally when I set the aperture ring on the lens to "A" and then set the aperture electronically through the camera. I still don't understand the root cause, but clearly the camera is happy when the body has control over the aperture position. Being new to the Pentax system, I had not realized that I could set the aperture on an FA or A lens via the camera. Coming from a Canon system, I had enjoyed the nostalgia of a lens mounted aperture ring, but I honestly find adjustment from the camera dials more convenient. Again, thanks for this note. Camera is effectively 100% functional if I just leave all my lenses on "A"

Dave, also try contacts cleaning, body and lens. If you've already done that, try again. I have read that this can be a weirdly difficult problems on other cameras. Wouldn't surprise me if Pentax was not immune.

sculptor666 · 10-02-2017, 06:44 PM

i dont know if the 645 has a "use aperture ring" setting in the menu?

postnobills · 10-03-2017, 07:09 PM

Originally posted by sculptor666

i dont know if the 645 has a "use aperture ring" setting in the menu?

It does not. Moving the aperture ring from the A position sets it to the manually selected aperature.

09-26-2017, 12:39 AM	#1
Dave645 New Member Join Date: Sep 2017 Posts: 4	645z Shutter sometimes does not fire The shutter on my 645z will sometimes not fire when I press the shutter button or when I go into live view. Has anyone else encountered this issue? As far as I can tell, it seems to be a software issue and not a problem with the hardware. To be clear, the rest of the camera behaves as if an image is being taken. The mirror goes and the sensor takes an all black image, and saves it to the card. The camera is responding, but the shutter itself does not fire. I can seem to reset the camera in one of two ways. First, if I take off the lens and put into live view, the mirror goes up, but no shutter. I repeat, and the next time the shutter goes up and normal live view operation ensues. Or, when in live view, I can operate the depth of field preview button twice, and the camera will return to normal operation I am running the latest firmware, 1.30. I have been trying to reinstall the firmware manually but cannot get the camera to recognize an SD card with the 1.30 binary file on it. Has anyone else managed to reinstall the same firmware version? Thanks, David

09-26-2017, 04:03 PM	#3
postnobills Forum Member Join Date: Jul 2017 Photos: Gallery Posts: 51	Start out with a camera reset. Wrench Icon > 3 > bottom line. Then navigate to C > 5 > Reset Custom Functions. When doing a firmware update the SD card is only recognized in Slot 1. Make sure you have a fully charged battery. Try a different card. Then get back to us. Last edited by postnobills; 09-26-2017 at 04:10 PM.

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09-26-2017, 01:40 AM	#2
D1N0 Pentaxian Join Date: May 2012 Location: --- Photos: Gallery Posts: 6,802	Sounds like to a shutter starting to fail to me.

09-27-2017, 01:29 PM	#4
Dave645 New Member Join Date: Sep 2017 Posts: 4 Original Poster	Thanks for the ideas. Resetting the camera to factory settings does not fix the issue. I am fairly certain that the shutter mechanism itself is just fine. Everything works perfectly when I have a D-FA lens attached to the camera. I cannot seem to reinstall the firmware. I am using a formatted SD card with the binary file in the root directory, in slot 1, with a full battery. My only guess is that the update procedure only works if there is an older version of the firmware on the camera, but I have not gotten confirmation on this. I can now reproduce the problem in a deterministic way, and it appears to be related to the aperture closing mechanism. If the aperture lever in the camera does not move (i.e., the lens is set wide open) then the camera will take one frame properly. On subsequent frames though, the shutter will not open. Allowing the aperture lever to move again, either by stopping the lens down, or removing it from the camera and then taking some frames will reset the camera to normal operation. This happens will all of the older lenses I have tried that have the aperture mechanism controlled by the camera. When using a modern D-FA lens, the shutter never fails to fire. So, I have narrowed it down to something funky happening with the mechanical aperture mechanism that then for reasons I cannot fathom, affects the shutter. The practical effect right now is that I cannot use older A and FA lenses wide open.

09-28-2017, 07:24 AM	#5
iCrop Site Supporter Join Date: Mar 2007 Location: Tucson Photos: Gallery Posts: 292	Originally posted by Dave645 I can now reproduce the problem in a deterministic way, and it appears to be related to the aperture closing mechanism. If the aperture lever in the camera does not move (i.e., the lens is set wide open) then the camera will take one frame properly. On subsequent frames though, the shutter will not open. Allowing the aperture lever to move again, either by stopping the lens down, or removing it from the camera and then taking some frames will reset the camera to normal operation. This happens will all of the older lenses I have tried that have the aperture mechanism controlled by the camera. When using a modern D-FA lens, the shutter never fails to fire. So, I have narrowed it down to something funky happening with the mechanical aperture mechanism that then for reasons I cannot fathom, affects the shutter. The practical effect right now is that I cannot use older A and FA lenses wide open. Does the shutter operate properly if the lens aperture ring is in the 'A' position? If so, you should be able to shoot wide open using the aperture control on the camera. Good luck.

09-28-2017, 02:00 PM	#6
Dave645 New Member Join Date: Sep 2017 Posts: 4 Original Poster	Yes! Great suggestion, thank you. The camera operates 100% normally when I set the aperture ring on the lens to "A" and then set the aperture electronically through the camera. I still don't understand the root cause, but clearly the camera is happy when the body has control over the aperture position. Being new to the Pentax system, I had not realized that I could set the aperture on an FA or A lens via the camera. Coming from a Canon system, I had enjoyed the nostalgia of a lens mounted aperture ring, but I honestly find adjustment from the camera dials more convenient. Again, thanks for this note. Camera is effectively 100% functional if I just leave all my lenses on "A"

09-29-2017, 07:12 AM	#7
iCrop Site Supporter Join Date: Mar 2007 Location: Tucson Photos: Gallery Posts: 292	Originally posted by Dave645 Yes! Great suggestion, thank you. The camera operates 100% normally when I set the aperture ring on the lens to "A" and then set the aperture electronically through the camera. I still don't understand the root cause, but clearly the camera is happy when the body has control over the aperture position. Being new to the Pentax system, I had not realized that I could set the aperture on an FA or A lens via the camera. Coming from a Canon system, I had enjoyed the nostalgia of a lens mounted aperture ring, but I honestly find adjustment from the camera dials more convenient. Again, thanks for this note. Camera is effectively 100% functional if I just leave all my lenses on "A" Glad to help. That's what this forum is for.

09-29-2017, 01:08 PM	#8
texandrews Moderator Join Date: Apr 2014 Location: Baltimore Photos: Albums Posts: 3,390	Originally posted by Dave645 Yes! Great suggestion, thank you. The camera operates 100% normally when I set the aperture ring on the lens to "A" and then set the aperture electronically through the camera. I still don't understand the root cause, but clearly the camera is happy when the body has control over the aperture position. Being new to the Pentax system, I had not realized that I could set the aperture on an FA or A lens via the camera. Coming from a Canon system, I had enjoyed the nostalgia of a lens mounted aperture ring, but I honestly find adjustment from the camera dials more convenient. Again, thanks for this note. Camera is effectively 100% functional if I just leave all my lenses on "A" Dave, also try contacts cleaning, body and lens. If you've already done that, try again. I have read that this can be a weirdly difficult problems on other cameras. Wouldn't surprise me if Pentax was not immune.

10-02-2017, 06:44 PM	#9
sculptor666 Pentaxian Join Date: Dec 2013 Location: PA Photos: Gallery Posts: 675	i dont know if the 645 has a "use aperture ring" setting in the menu?

10-03-2017, 07:09 PM	#10
postnobills Forum Member Join Date: Jul 2017 Photos: Gallery Posts: 51	Originally posted by sculptor666 i dont know if the 645 has a "use aperture ring" setting in the menu? It does not. Moving the aperture ring from the A position sets it to the manually selected aperature.

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