[sachmo]

Hi All,

Bought my K50 in 2015. Light shutter count at just under 2000.

Recently, when I attempt to take photos, the LCD in the back goes completely black and the camera appears to have a weird power issue where none of the buttons are responsive -- including the on / off switch. The odd thing is that in the viewfinder, I can still see the electronic numbers as if there is still some part of the circuitry that is powered on.

The only way to reset the camera in this case is to pull the battery, place it back in, and power on. Boot up and camera menu works normal, until I attempt to take a picture and I have the same issue again.

I have tried ordering new batteries and charging them fully, cleaning the electrical contacts on both the batteries and inside the camera battery holder, also tried using a AA adapter with eneloops. I have also upgraded to latest firmware (version 1.10). I can occasionally get the camera to work if I fiddle with long enough by rebooting it enough times, but it usually does not work and is unreliable.

When the camera does work and takes pictures, they appear normal -- as in exposed properly.

I am an engineer and would guess that when I press the power button, something in the camera is drawing more current than the battery pack can handle -- the shutter begins to activate, the voltage suddenly drops, and then most of the circuitry is left in a weird error state except maybe the viewfinder which might have lower voltage chips. This is just a guess, wouldn't know unless I took it apart and actually started metering the circuit.

I am trying to figure out if this is an aperture block failure or something else. Also wanted to add that I only use older, manual pentax lenses, but I think the aperture mechanism also controls the shutter? Not sure, reading through all these threads on the issue it sounds like it is related.

I am looking into repair options and have sent an email to Precision Camera who has yet to respond to my issue or tell me what exactly they will do if this is in fact the dreaded aperture block failure. If this is the solenoid causing the issue, I don't see how simply replacing it for another will really solve it. I would expect it to last another 18 months or so and then die again, which doesn't seem worth the cost of repair. Would rather invest that money in a new camera body.

I was writing here to see if anyone else experience a similar issue and if they were able to resolve it.

Any insight would be appreciated, thank you.

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Last edited by sachmo; 06-18-2020 at 11:07 AM.

[The Squirrel Mafia]

Try doing a factory reset. That might fix the quirks.

Another possibility could be a corrupted SD card. It can cause issues with the camera.

[Not a Number]

Check the "sticky" subjects for relevant threads on this subject.

In particular:

Detection of aperture block/diaphragm-block failure/stuck solenoid K-30, K-50, K500 - PentaxForums.com

[sachmo]

Check the "sticky" subjects for relevant threads on this subject.

In particular:

Detection of aperture block/diaphragm-block failure/stuck solenoid K-30, K-50, K500 - PentaxForums.com

I tried swapping SD cards and had the same issue.

With regards to the detection of aperture block failure thread, I can't get to step 2 in the workflow which involves taking a picture as the camera shuts off. On the few occasions where the camera does not shut off, the pictures appear properly exposed.

[automorphism]

This does not sound like a regular aperture block failure. Most other people just get black frames, and the camera works fine with the aperture ring on manual.

[stevebrot]

Definitely not aperture block failure. The usual suspects (none specific to the K-50 or Pentax) might be power (bad or weak battery), bad main board, bad on/off switch, water/moisture intrusion, being dropped, and other stuff.


Steve

[stevebrot]

K50 Aperture Block Failure?

FWIW, if your K-50 was to have aperture block problems, it would have surfaced in the first 10 to 18 months of ownership. The issue is age-related and is not the result of wear or high usage. A close friend of mine had aperture block/mirror control failure (the two often occur together) on her late-2013 K-50 at 13 months in January 2015. Ricoh/Pentax honored the warranty and the fix by Precision has been good ever since.


Steve

[photogem]

FWIW, if your K-50 was to have aperture block problems, it would have surfaced in the first 10 to 18 months of ownership.

Some Pentax develope aperture-block during the first 10-18 month of ownership, but only some.

Most develop it later on, many for example when not used for a longer time.

The issue is age-related and is not the result of wear or high usage.

Because many develop the problem when not used for a long time, one could somehow say it is age-related, but

the body actually does not age in this case, it is simply magnetism.
But in other situations particular when higher shutter-count it is also a result of wear and high usage!
Because regularely used magnetism doesn't built up that strong but due to the fact that the body of the green China-solenoid is made out of PET
which wears worse compared to PTFE used in the white Japan-solenoid.

@sachmo:
when you check the steps for Detection of aperture block/diaphragm block failure and you won't be able to reach,
how is it with method #2 and Live-View?
You just switch Live-View on and look into your lens (must be at least an A-lens!)
In M-Mode you preselect aperture and then press the green button.
No solenoid in action!
The aperture-control-mechanism does not control the shutter but both are interlinked, work together.
Because of this any Pentax with a solenoid for aperture-control still works in M-Mode, i.e. the shutter works.

I daubt this is shutterrelated. Your idea about some part sucking suddenly energy sounds possible.


To me it sounds like a mainboard-problem.

I would not send it in for repair, too expensive, for this money you can buy a 2-nd hand K5!
If you shoot manual, the K5 is the better camera! And no solenoid but a stepper motor.
Sell your K50 for parts, any other step than disassembly for finding out if there are any contact problems (moisture, salt from living near the seaside?) are not worth it, even for this very low shuttercount.
A broken K50 (only if the solenoid is damaged) would cost you $ 80 +/- and then you do not really know it it is the mainboard.
A used K5 is not much more expensive and as you can sell the K50 it brings you that money in.
My suggestion! The K5 is really great for manual lenses. Only drawback: Live-View has no focus-peaking!
But then... a K5 works great with a Katzeye screen!

[stevebrot]

Some Pentax develope aperture-block during the first 10-18 month of ownership, but only some.

Most develop it later on, many for example when not used for a longer time.


Because many develop the problem when not used for a long time, one could somehow say it is age-related, but

the body actually does not age in this case, it is simply magnetism.
But in other situations particular when higher shutter-count it is also a result of wear and high usage!
Because regularely used magnetism doesn't built up that strong but due to the fact that the body of the green China-solenoid is made out of PET
which wears worse compared to PTFE used in the white Japan-solenoid.

@photogem...I suppose I should have been more specific and stated that to the best my knowledge, aperture block failure has not been reported in cameras less than about a year post-manufacture, regardless of use, and that almost all were out of warranty (one year) at the time the problem was reported here. You are absolutely correct that long periods of non-use has been a very common pattern, but might be coincidence. Who can say?

Simply magnetism does not wash with me, but if it allows one to weave a narrative consistent with the common fix, good enough.

As for the thread originator's problem, I concur that main board failure is a very likely cause and that the cost to repair is likely not cost-effective. I also concur that the problem is not aperture block.


Steve

[photogem]

Simply magnetism does not wash with me, but if it allows one to weave a narrative consistent with the common fix, good enough.

Based on which true actual experience (other than guessing)?

How many solenoids did you actually have in your hands, green Chinese ones and white Japanese ones?
And how many Pentax bodies with aperture block failure did you open and do research with?

[sachmo]

Hi photogem,

If I switch to Live-view, prior to taking an image, live view works fine. The moment I press the button to take a picture, the camera locks up (all buttons unresponsive, lcd screen turns off) as noted before. If I am in M mode, I can press the green button, and the camera will do the light metering properly. It's only when I actually try to take the photo, that I get the weird camera lock up.

I ultimately decided to buy a used K3 over sending the K50 in for repair. I would also agree that it's not worth it to spend ~$200 on a camera body that may have a lot of manufacturing issues, vs spending on a new (or used) body.

For someone in the future who faces this same issue, thread is here as well as a justification for my decision:
K50 body acting weird, time to upgrade camera body... Considering KP vs Sony A7 ii - PentaxForums.com

Initially I was looking at the KP and Sony A7, but ultimately went for a lightly used K3 for a much cheaper price which still feels like an upgrade from the K50.

[photogem]

I think this was a wise choice, the K3 is a very good body, very sound and reliable.

The A7 has the problem that the sensor is exposed and gets dirty very quickly. Otherwise of course due to focus-peaking and adaptability a very interesting body
for Pentax manual lenses. But I would still prefer the K3.