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What is seen when looking through the binoculars is blurry and not clear.
Chances are, there is dirt stuck inside the lens assembly. Unscrew the lens assembly and brush away any visible dirt on the lens with a soft brush or compressed air. Use a lens cloth lightly dabbed in lens cleaning solution to gently wipe the lens in order to remove tiny particles.
If the image is blurry from moisture, notice the curved patches where the lens is fogged. Leave the binoculars in a warm, dry place for a few days to see if the moisture is light enough to clear on its own. If there is no noticeable progress, place the binoculars inside an airtight bag or container along with a desiccant. Desiccants can be found online or at a store like Walmart. Leave the sealed binoculars for a few days to dry. The desiccant will absorb the moisture.
There is a line running through the image
If there is a noticeable line running through the image, the lens may be cracked. Attempt to to clean the lens in the ways described above in order to rule out dirt or moisture. If these methods do not work, the cracked lens must be replaced.
No matter what is done, the knob to focus is not adjusting
More often than not, debris is stuck in the crevices of the knob are the main focus for either knobs to be stuck. If the knobs are unable to turn, try taking the cap off to reveal if there is debris under there. Once the debris is located, use either a piece of cloth or a dust blower to remove the debris. Upon the removal, it should now function properly.
The image the user sees appears side by side, one object looks like two.
Make sure that the eyepieces are directly in line with each eye when in use. Pull up and down on each side of the binoculars to move the eye pieces closer or farther apart. Adjust until image is continuous and there are limited black edges in view.
The device is unstable when being held
In case of a loose lens or loose lens assembly, follow these steps for troubleshooting. First, undo the cap on the front of the binoculars. Once the cap is removed there will be a bolt that may need adjusting or replacement. It will require an appropriate flathead screwdriver to unfasten it. Once removed, check the screw/bolt to see if it is damaged. If it is, it needs replacing. If the screw is in good condition, then next check for cross threading. There may be shaking on the assembly if there is cross threading (the bolt wasn’t fastened correctly). Unscrew the bolt then screw it back in making sure it is properly adjusted and there is no longer any cross threading. If this solves the problem, reassemble the binoculars in the order it was disassembled.
Remove the cover by peeling from the center of the binoculars. Do the same procedure from each side until the skin is completely off. Apply liberal amount of glue along the edges of the binoculars. Slip the cover back on, making sure that the slit is aligned with the strap hook.