Originally posted by 35wailin I am considering upgrading my k50 to a k70 because of the aperture motor failure in the k30 and k50. I repaired my 50, but I dont fully trust it now.
I know the aperture motor in the K-30 was a known issue and was also used in the K-50.
Does anyone know if they re-engineered that part in the K-70 or would I be looking at the same issue down the road? If it is the same part, then I will keep my cash and shoot my K-50 until itnis completely worn out and hope for the best that the ap. motor doesnt fail again.
TSM is essentially correct in what he says. There have been a few issues reported with the K-S2, but it is just now reaching the age where you'd expect serious problems to emerge; I've heard 'hear-say' stories of a few issues with the K-70 in Germany. I 'm not a materials scientist - I don't know whether Pentax fully understands this issue, and I do have questions as to whether their supplier could go back to the exact formula that apparently served them well for thirty years.
Incidentally, the issues with these cameras is a solenoid - a version of electromagnet - not a motor per se. There are instructions here how to replace the solenoid. Another alternative, which I plan to follow if the DIS becomes too bad before I get around to purchasing a KP, is to use lenses, such as M42, Pentax-M, or Pentax-FA lenses with aperture ring so you can control the aperture at the lens, because the failure comes in the mechanism that enables aperture to be controlled from the body.
This all matters because I believe the K-70 does use the basic design that the K-30 and K-50 used, a design which apparently goes back to the early days of the KA-mount in the early 1980s (*). Pentax has definitely said that the KP uses the K-7/5/3 design instead, but I don't remember their ever giving a definite answer concerning the K-70 design,
(*) I purchased a Pentax Super Program in 1983, and mostly retired it in 1995, but I still have it and its aperture control still works on the rare occasions when I use it. I purchased a K-30 thirty years later {2013} and as of several months ago it shows Dark Image Syndrome symptoms on the first shot each day - but nothing after that. I believe the two cameras have the same aperture control design, with parts sourced differently.