my fix of the K-30 aperture problem without disassembly

My findings are far from "scientific," partly b/c I haven't tried shooting in all applicable settings, etc.

For what it's worth, I stopped shooting with the K50 about 14 hours, leaving the AA adapter with AAs in the camera.

Turned on the camera in the auto mode and the kit 18-55 lens.  Went into a room lit with late afternoon cloudy light coming out of a window.

First shot was badly underexposed.  Following 4 shots seemed okay, perhaps slightly underexposed.  (I don't have the expertise to say, not knowing what this camera/lens/auto settings should optimally produce under these lighting conditions.)

Replaced the AAs with Lithium-Ion battery, which is still fully charged according to the K50's sensors.  (I fully charged it with the charger a couple of days ago and have taken 50 shots with this battery since, some with LiveView and/or flash.)

The photos with the Lithium-ion were similar to the ones I had just shot with with the AAs.

Note:  When I was using the K50 regularly with the AA adapter a couple of years ago, the K50 seemed to find that non-rechargeable alkaline AA batteries were depleting after much less usage than I would have expected.  Don't know what is going on there and haven't done any Internet research as to whether K50s have problems with AA batteries.

Additional note:  AFAIK, there are no AA adapters or battery grips with AA functionality for the K70.  (If I'm wrong on this, I hope some reader corrects me.)