[henrywmk]

Need help, recommendation and advice from experts:
Using fine with this Tamron lens for several months. Unfortunately, abnormal was found intermittently while travelling at Korea.
Symptom: AF mode indication was strangely/suddenly changed to MF while trying to take a picture, and aperture value was abnormally flashing at the display. Even though you can still press the shutter to take a picture, the image certainly was in bad condition. Sometimes, it'll back to normal within a short time period. The worst case was replaced with a fresh new battery. I am not quite sure whether this was a battery issue, lens problem or K-x trouble...Should I bring the lens to Tamron or calling help at Pentax? Pentax may not provide any warranty service since I was using a 3rd party lens.
Look forward to hear your reply. Thanks.

[Adam]

It sounds like the lens contacts might have been dirty or the lens was not properly mounted. Are you sure the lens was latched in place? Have you tried cleaning the mount?

There might be a problem with the lens's electronics should you answer 'yes' to both of the above questions.

[AOShep]

Did you drop it or hit the lens barrel on something sold? I have the same lens and it fell out of my bag when I didn't properly zip it closed. Thought I lost it for sure. It would not give an aperture setting. My camera would display F--- for the aperture. After messing with it for awhile I discovered that if I twisted the focus ring slightly it would pop back and I could use it for awhile. Sense it is no longer my primary lens I am putting off getting it repaired.

[henrywmk]

Thanks for the replies

I had already cleaned the mount twice and make sure the lens was latched in good condition. Unfortunately, the bad symptom was still persisted. I think I never clashed it before since Kx was my first DLSR. I really love it and care about it.

Any suggestion or advice for me??? Please kindly help.