Camera wont focus or take picture

mediumjohn

New member
I have had my D40 for about 4 years and every now and then it will stop focusing and won't take the picture. Now here is the weird part, if I take the lens off and put it back on it starts working again. Any help is greatly appreciated!!!!!
 
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Fred Kingston

Senior Member
Nothing weird about it... The lens has electrical contacts on it that mesh/meet with electrical contacts on the body... The lens electrically talks to the camera body to tell the body about the lenses characteristics... If it doesn't make good electrical contact, the body has no way of doing anything...

​Examine and make sure the contacts between the two components are clean... I'll caution you about cleaning as you can make a mess if done incorrectly...
 

Fred Kingston

Senior Member
There are contact cleaning solutions made specifically for electrical contacts... If you search on Amazon specifically for "electrical contact cleaner"... you'll get many hits... most are spray cleaners and should be used very judiciously... IOW, spray on a rag or q-tip... and rub the contacts... Don't spray into the contacts or camera... There are also pen style cleaners in the same search that are like small hard rubber/abrasive erasers... Again, be very careful as they abrad small particles are released, which you don't want to get in your lens or camera... Get one of the camera rubber bulb blowers while you're at it to blow out any dust while you're cleaning... I'd probably start with a microfiber cloth wrapped around a small stick/blade and dipped in a bit of Isopropyl alcohol to just wipe the contacts before moving to the other more serious solutions...

​Good luck...
 
Go to the drug store or some hardware stores and get some denatured alcohol. It is cleaner than standard rubbing alcohol. This is what we used when cleaning contacts at the TV station I worked at. Also hold the camera lens down while you are cleaning so if anything does fall it will fall away form the inside of the camera.
 
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