K-50 black frames (but not aperture-related)

hugo · 08-14-2019, 01:23 PM

Hi Pentax friends,

Randomly have issue with my K-50.
Most of the times, the pictures are plain solid black.
Other occasions you can still see a "picture" but the colors are corrupted to the point where only 2-3 colors show (see picture), making an almost unreadable picture at the end.
The Live View on LCD already exhibits the issue before taking the picture. (i.e. I turn on camera, turn on Live View and the display is all black, or more rarely showing corrupted colors). (Yes, I did remove the cover on the lens! if you're about to ask

)
I've browsed the forum and of course came across the "aperture block failure issue" but I don't think this is my issue (reason is, the lenses are not part of the equation, even without any lens attached I see the same behavior on the LCD)

The mirror mechanism does work.
Upgraded to latest firmware, no change.
Charger battery fully, no change.
Tried a few bursts of continuous shooting, no change.
Anything else to try ?

Sounds like a defective CMOS to me but curious to hear your thoughts.

Thanks for reading!
Hugo

Attached Images

View Picture EXIF

View Picture EXIF

Last edited by hugo; 08-14-2019 at 08:06 PM. Reason: Added picture

**pepperberry farm** · 08-14-2019, 02:23 PM

try a different SD card...

hugo · 08-14-2019, 08:03 PM

Originally posted by pepperberry farm

try a different SD card...

Thanks for the suggestion however, even without any SD card in the camera and pressing LV you can see something's wrong (like I've mentionned, most of the times it's all black, and in some occasions, there is a picture but corrupted.
See photo taken (with my phone) of the k-50 Live View LCD just before it suddenly went black again...

photogem · 08-19-2019, 11:17 PM

I'd try first a factory reset. It the problem remains, yes, a defective sensor then is a possibility, or mainboard.

And yet, it could be both, i.e. defective solenoid as well.

madphys · 08-20-2019, 05:09 AM

Try updating firmware, if possible.

hugo · 08-21-2019, 06:29 AM

Thanks again for the suggestion, alas this has been tried already (Factory reset, firmware upgrade to latest) - and no changes.

photogem · 08-21-2019, 09:49 AM

Then most likely the sensor is damaged. Only usable for parts.

08-14-2019, 08:03 PM	#3
hugo New Member Join Date: May 2008 Location: Montreal, QC - Canada Posts: 3 Original Poster	Originally posted by pepperberry farm try a different SD card... Thanks for the suggestion however, even without any SD card in the camera and pressing LV you can see something's wrong (like I've mentionned, most of the times it's all black, and in some occasions, there is a picture but corrupted. See photo taken (with my phone) of the k-50 Live View LCD just before it suddenly went black again... Attached Images

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08-14-2019, 02:23 PM	#2
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 18,178	try a different SD card...

08-19-2019, 11:17 PM	#4
photogem Pentaxian Join Date: Apr 2015 Location: Winterthur Posts: 757	I'd try first a factory reset. It the problem remains, yes, a defective sensor then is a possibility, or mainboard. And yet, it could be both, i.e. defective solenoid as well.

08-20-2019, 05:09 AM	#5
madphys Forum Member Join Date: Dec 2007 Location: Riga, Latvia Posts: 97	Try updating firmware, if possible.

08-21-2019, 06:29 AM	#6
hugo New Member Join Date: May 2008 Location: Montreal, QC - Canada Posts: 3 Original Poster	Thanks again for the suggestion, alas this has been tried already (Factory reset, firmware upgrade to latest) - and no changes.

08-21-2019, 09:49 AM	#7
photogem Pentaxian Join Date: Apr 2015 Location: Winterthur Posts: 757	Then most likely the sensor is damaged. Only usable for parts.

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