hello . error nikon d40x

* First, Remove Its Battery.

• Remove the Bottom Base Cover Plate
• Removed All Screw Holding the Base Cover
• Proceed Removing All Screws in a Sysmetic Clockwise Order
• Remove All Screws and Aside It on a Piece of Tissue Paper
• View of the D40 DSLR Base With Cover Removed.
• The Gear Operating the Shutter
• Lightly Move the Gear & Inspect for Contamination
• A Closer View of the Gear Seen Through a Magnifying Glass
• Repeat About 5 Cycles.
• Apply New Grease Between Gears

* Spray a Little at a Time & Move Th Gears

• Move the Gears 5 Cycles to Spread Out Grease

* Insert Battery & Test Before Closing Up Cover.

• Close Back Base Cover & Have Fun!

If you want to watch all these instruction with images then open Nikon D40 Manual.