Pentax KX - can't change aperture or

aboslett · 05-10-2020, 05:57 PM

Hi all. I recently bought a Pentax KX off eBay. Low shutter count and apparently good working camera. However, I can't seem to get the aperture dial to work. When I have the camera in manual mode, The aperture will go down for a couple stops and then all of a sudden go back up. It won't stick on anyone aperture value outside of the ones at the very extreme. I don't know what's going on. I also can't switch the +- stops. Always drifts to 3+ in manual mode. Thoughts?

Not a Number · 05-10-2020, 07:04 PM

Maybe the white aperture solenoid was harvested and a defective green one put in its place.

Get your money back.

**stevebrot** · 05-10-2020, 07:06 PM

By aperture, is it safe to assume you mean the e-dial at top rear of the camera?

Do you have a copy of the manual? If not, you can download from the Ricoh Imaging Japan Web site.

Operation Manuals Download : Support & Service | RICOH IMAGING

The default behavior of the e-dial in M-mode is to change the shutter speed. To change aperture, press the +/-Av button while turning the e-dial. Automatic exposure compensation (+/-) is not available in M-mode. The meter-recommended exposure is displayed on the rear LCD in the +/- pane. Adjust shutter speed and aperture to center the indicator in the +/i pane.

Neither the set shutter speed nor the set aperture should change by itself once set in M-mode. The only exception is if the green button is pressed. In that case, the meter reading is applied to change the settings. How they are changed is explained in the manual and are configured in the capture menu.

The graph display in the +/- pane will change according to the light coming through the lens. You are safe to ignore this unless you are wanting to change the exposure.

One more thing, in regards to metering...unless you are confident as to why amd how you might use spot metering, it is best to use either multi-segment or center-average as the meter setting.

If behavior is other than what I described, there may be a problem with the camera, meaning that a request to the seller to return might be a good idea.

Steve

**stevebrot** · 05-10-2020, 07:08 PM

Originally posted by Not a Number

Maybe the white aperture solenoid was harvested and a defective green one put in its place.

??????? I guess the post might be interpreted as aperture control failure during exposure, but I took it to mean difficulty setting aperture and having the value stick.

Steve

builttospill · 05-10-2020, 08:21 PM

The aperture ring on a KX is always on the lens, not the camera.

I'm guessing aboslett purchased a K-x, very different from the 1975 KX film camera. Are you using a zoom lens with a variable aperture? If you set the aperture to an extreme, i.e., wide open, and then zoom in with the lens, the aperture will adjust automatically, becoming smaller (higher f/stop).

What lens are you using with the K-x? Do the connecting levers and contacts look straight and clean? When you say the +- being at +3, are you talking about exposure compensation? If so, here's a thread about this on the K-x: ev adjust in manual mode on k-x - PentaxForums.com

**photogem** · 05-11-2020, 12:46 AM

Originally posted by aboslett

Hi all. I recently bought a Pentax KX off eBay. Low shutter count and apparently good working camera. However, I can't seem to get the aperture dial to work. When I have the camera in manual mode, The aperture will go down for a couple stops and then all of a sudden go back up. It won't stick on anyone aperture value outside of the ones at the very extreme. I don't know what's going on. I also can't switch the +- stops. Always drifts to 3+ in manual mode. Thoughts?

With "aperture dial" you mean the dial left to the AF/AE-L button, i.e. the thumbwheel?

If so, this is a common issue with the K-x, the seller should have noticed because this problem starts slowly and then gets worse, it is a contact problem and pretty easy to repair and it is so that even in M-Mode you can't dial prober values:
Tutorial E-Dial (Thumbwheel) Repair Pentax K-r, K-x and K-m (K2000) - PentaxForums.com

It can happen with low shuttercount because the thumbwheel isn't WR and with dirty/sweaty fingers dirt can enter pretty easy.
But also just moisture through humidity in the air, particular near the sea or lakes can cause it!

So let us know.

Jan178 · 05-11-2020, 05:02 AM

Fixed the thumbwheel of my K-x by spraying with electronic cleaning spray. Batteries out and just a small spray into the wheel and couple turns, then let dry for a moment. Cheap, fast and easy, has been working for about two years now.
If that won´t help then some of the above methods

edit: ignore this advise!!

**photogem** · 05-11-2020, 06:43 AM

We had this discussion before, so just a short answer:

I have plenty experience with all sorts of electronic cleaning sprays. So often used in Audio just for volume potentiometers, it NEVER EVER worked on long term!
I have studied the effects there plenty of times, even under the microscope.

It can work for a time but often does more damage than good over a longer period.

I had several K5's (which are WR) were people used even high quality electronic cleaning spray, even so called tuner-spray, the most sensitive... and it was the final exodus!

My strong recommendation: Stay away as far as possible from such solutions!

Jan178 · 05-11-2020, 09:00 AM - **1 Like**

Originally posted by photogem

My strong recommendation: Stay away as far as possible from such solutions!

Hmm, i guess i have to rethink my habits then. I´ve been using those sprays for amplifiers and all things with contacts with good results, but yeah, it might not be good after all in the long run. Cheap and easy, of course... Just never thought about it too much

Thanks for the insight!

05-10-2020, 05:57 PM	#1
aboslett New Member Join Date: Jun 2019 Posts: 7	Pentax KX - can't change aperture or Hi all. I recently bought a Pentax KX off eBay. Low shutter count and apparently good working camera. However, I can't seem to get the aperture dial to work. When I have the camera in manual mode, The aperture will go down for a couple stops and then all of a sudden go back up. It won't stick on anyone aperture value outside of the ones at the very extreme. I don't know what's going on. I also can't switch the +- stops. Always drifts to 3+ in manual mode. Thoughts?

05-11-2020, 05:02 AM	#7
Jan178 Pentaxian Join Date: Apr 2013 Location: Rovaniemi, Finland Photos: Albums Posts: 766	Fixed the thumbwheel of my K-x by spraying with electronic cleaning spray. Batteries out and just a small spray into the wheel and couple turns, then let dry for a moment. Cheap, fast and easy, has been working for about two years now. If that won´t help then some of the above methods edit: ignore this advise!! Last edited by Jan178; 05-11-2020 at 09:02 AM. Reason: bad advise

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05-10-2020, 07:04 PM	#2
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 7,685	Maybe the white aperture solenoid was harvested and a defective green one put in its place. Get your money back.

05-10-2020, 07:06 PM	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 38,869	By aperture, is it safe to assume you mean the e-dial at top rear of the camera? Do you have a copy of the manual? If not, you can download from the Ricoh Imaging Japan Web site. Operation Manuals Download : Support & Service \| RICOH IMAGING The default behavior of the e-dial in M-mode is to change the shutter speed. To change aperture, press the +/-Av button while turning the e-dial. Automatic exposure compensation (+/-) is not available in M-mode. The meter-recommended exposure is displayed on the rear LCD in the +/- pane. Adjust shutter speed and aperture to center the indicator in the +/i pane. Neither the set shutter speed nor the set aperture should change by itself once set in M-mode. The only exception is if the green button is pressed. In that case, the meter reading is applied to change the settings. How they are changed is explained in the manual and are configured in the capture menu. The graph display in the +/- pane will change according to the light coming through the lens. You are safe to ignore this unless you are wanting to change the exposure. One more thing, in regards to metering...unless you are confident as to why amd how you might use spot metering, it is best to use either multi-segment or center-average as the meter setting. If behavior is other than what I described, there may be a problem with the camera, meaning that a request to the seller to return might be a good idea. Steve

05-10-2020, 07:08 PM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 38,869	Originally posted by Not a Number Maybe the white aperture solenoid was harvested and a defective green one put in its place. ??????? I guess the post might be interpreted as aperture control failure during exposure, but I took it to mean difficulty setting aperture and having the value stick. Steve

05-10-2020, 08:21 PM	#5
builttospill Pentaxian Join Date: Jun 2009 Location: Utah, Idaho Photos: Gallery Posts: 2,007	The aperture ring on a KX is always on the lens, not the camera. I'm guessing aboslett purchased a K-x, very different from the 1975 KX film camera. Are you using a zoom lens with a variable aperture? If you set the aperture to an extreme, i.e., wide open, and then zoom in with the lens, the aperture will adjust automatically, becoming smaller (higher f/stop). What lens are you using with the K-x? Do the connecting levers and contacts look straight and clean? When you say the +- being at +3, are you talking about exposure compensation? If so, here's a thread about this on the K-x: ev adjust in manual mode on k-x - PentaxForums.com

05-11-2020, 12:46 AM	#6
photogem Loyal Site Supporter Join Date: Apr 2015 Posts: 1,278	Originally posted by aboslett Hi all. I recently bought a Pentax KX off eBay. Low shutter count and apparently good working camera. However, I can't seem to get the aperture dial to work. When I have the camera in manual mode, The aperture will go down for a couple stops and then all of a sudden go back up. It won't stick on anyone aperture value outside of the ones at the very extreme. I don't know what's going on. I also can't switch the +- stops. Always drifts to 3+ in manual mode. Thoughts? With "aperture dial" you mean the dial left to the AF/AE-L button, i.e. the thumbwheel? If so, this is a common issue with the K-x, the seller should have noticed because this problem starts slowly and then gets worse, it is a contact problem and pretty easy to repair and it is so that even in M-Mode you can't dial prober values: Tutorial E-Dial (Thumbwheel) Repair Pentax K-r, K-x and K-m (K2000) - PentaxForums.com It can happen with low shuttercount because the thumbwheel isn't WR and with dirty/sweaty fingers dirt can enter pretty easy. But also just moisture through humidity in the air, particular near the sea or lakes can cause it! So let us know.

05-11-2020, 06:43 AM	#8
photogem Loyal Site Supporter Join Date: Apr 2015 Posts: 1,278	We had this discussion before, so just a short answer: I have plenty experience with all sorts of electronic cleaning sprays. So often used in Audio just for volume potentiometers, it NEVER EVER worked on long term! I have studied the effects there plenty of times, even under the microscope. It can work for a time but often does more damage than good over a longer period. I had several K5's (which are WR) were people used even high quality electronic cleaning spray, even so called tuner-spray, the most sensitive... and it was the final exodus! My strong recommendation: Stay away as far as possible from such solutions!

05-11-2020, 09:00 AM - 1 Like	#9
Jan178 Pentaxian Join Date: Apr 2013 Location: Rovaniemi, Finland Photos: Albums Posts: 766	Originally posted by photogem My strong recommendation: Stay away as far as possible from such solutions! Hmm, i guess i have to rethink my habits then. I´ve been using those sprays for amplifiers and all things with contacts with good results, but yeah, it might not be good after all in the long run. Cheap and easy, of course... Just never thought about it too much Thanks for the insight!

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