Wont always power on, also doesnt auto focus

Appears that the auto focus mechanism is not working, This anomaly is most obvious in lower light situations when focusing is much more critical.

If the camera was new and two months old I would either return it for another one or have Nikon repair the lens assembly under the terms of its warranty.

That means that there isn't enough contrast in order for the camera to get a subject in focus properly, if you can set back a little more that can help. The other option would be to have the camera focused where you want and switch to manual focus (which will leave the focus the auto focus found) and shoot the picture.

How hot did it get in the glove box of your car?

1. Make sure you will install a new or fully charged battery/batteries into your camera. 2. Clean the battery contacts. a. Remove the battery/batteries and the memory card from your camera, then wipe the battery contacts with a soft, clean cloth. b. Reinstall the battery/batteries into your camera. Please make sure that you are installing a fresh/ fully charged battery c. Without the memory card, turn your camera on. (If it works then it?s your memory card that is faulty) 3. Please test with the a different battery If you do not have access to another battery Try these steps instead: Please take the battery out of the camera. b. Insert the charger into the unit from the main socket and turn the camera on. If the camera works you will need to replace the battery. If you camera doesn?t switch on you will need to order a No power repair or a new cable. This camera has an auto lens. Which means it will focus automatically every second, which makes this clicking sound. You can turn this option off: 1: Go into the menu 2: Chose option Cam Settings 3: Switch AUTO focus to single lens and click OK.

Perhaps it is a focusing problem- try it on manual focus setting to see if the problem still persists...

Did it get dropped when the camera was open? If so it could have made the lens pop out more on one side. I'm not sure how to really explain it. When you open the camera, the thing that comes out might be off track I guess you could say. What setting are you using it on?

problem in lens censer replace it

If u r shooting in low light use flash. Normally switch to auto focus.

I had this problem and just realised it today. I found out that it was a a settings problem. What I had done without realising was I had my "AE-lock" button functioning as "AF-ON" which meant that my autofocus would only turn on when I held the shutter half-way and pressed that button. Once I turned this function back to its original state of "AF-Lock" as opposed to "AF-ON", it worked fine.
My symptoms were: • soft mechanical noise when holding the shutter (i thought it was trying to focus but couldn't. I thought the mechanics for the AF were faulty) • Couldn't take photos unless they were in the set conditions (which makes sense because it was locked on a certain setting until I pressed the AF-ON button).
My camera is only a few months old so I wasn't convinced it was faulty/broken. Make sure you test all of your settings and go through each of them before you chalk it down to equipment error.
Hope this helps.

Sounds like you need to get your camera fixed by Nikon.

However, you say the auto focus stopped working, you didn't switch to a lens that uses a mechanical focus linkage do you? The D40 only supports lenses with AF-S or AF-I type autofocus drives. AF-D and AF-G types without AF-S or AF-I don't autofocus.

Also, check that the A/M switch on the lens is in the correct position.

Manual focusing is quite difficult to do accurately with an AF camera. The screen inside the camera is not optimized for this. If you are sure you are focusing accurately but the pictures you take are still out of focus, the mirror may need adjusting. I can provide further info on this if you require, but if you're within warranty, i'd recommend that route first.