Originally posted by ydenk Can aperture cleaning resolve this problem? I would like to use a local repair shop and they have suggested cleaning is a common fix, but solenoid parts replacement might be problematic.
For sure don't use that local repair shop if they said this.
Then they talk nonsense³:
- ABF (Aperture-block-failure) happens because the solenoid is stuck.
- One does not replace parts of the solenoid but the whole solenoid:
Why you shouldn't file/sand the plunger of the green Chinasolenoid but replace it - PentaxForums.com
- Suggesting to clean the aperture itself indicates that they think it is a lens/diaphragm problem, i.e. sticky aperture/blades
This does never lead to ABF but only to problems with this particular lens, other lenses work alright
The only real solution is exchanging the solenoid for a true DSLR solenoid made in Japan:
A LITTLE BIT OF HISTORY: Development of the solenoid in Pentax cameras - PentaxForums.com