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Old Jun 03, 2013, 02:01 PM
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FREQUENTLY ASKED QUESTIONS (FAQs) - under construction

Camera Operation Problems
Camera Function Questions

BATTERY AND CMOS/LENS MAINTENANCE

1. Opening the case

The case has a top and bottom piece held together by two screws on the bottom front corners and two interlocking tabs/lugs on the back. Remove the two screws, lift the front of the case slightly, and push it towards the back (away from the lens) to remove the bottom piece and expose the circuit board.



There are three tiny screws securing the circuit board to the case top, but you will never need to remove these for normal maintenance.


2. Replacing the battery

The battery simply plugs into socket on the circuit board, and it has a key on the plug so it cannot be plugged in with wires reversed. The plug can be quite hard to remove, so a slight side-to-side rocking action with a thumb nail or NON-METALLIC tool in the gap between the plug and circuit board socket can help free it without exerting excessive force on the circuit board. Note the circuit board is long and narrow on that corner, and that portion is not secured to the case top when the bottom half is removed. Apply a little pressure with your thumb on the circuit board so it doesn't flex when removing the battery plug. NEVER PULL ON THE BATTERY WIRES to remove the plug! Plug in the new battery, re-position the cell and battery wires, and replace the case bottom when done. Note that the Mobius stock batteries have a small circuit board soldered to the battery tabs. This board has an IC chip that protects the cell from being over-charged or over-discharged. While this protection is redundant and a back-up to similar protection circuits in the camera itself, use of stock batteries is highly recommended to assure this added level of battery protection.


3. Replacing the CMOS imager module

NOTE: The camera battery should be removed before doing this (see item 2., above)! The pictures referenced below incorrectly show the battery still connected!

The CMOS module is press fit into a ribbed securement structure on the case. Because the CMOS ribbon cable is very short and can be damaged easily, it's advisable to first slide the ribbon cable from it's socket before the module is extracted. The ribbon cable slides into a socket on the circuit board and is clamped in place by a hinged clamping tab.


The cable is released for removal by gently lifting up on the aft edge of the clamping tab with a thumb nail or NON-METALLIC tool, such as a toothpick.



Gently slide the ribbon cable out of the socket with a NON-METALLIC tool such as a toothpick.


Now the CMOS module can be extracted from the case, but it is a very tight fit and should be done carefully. I find the best method is to use a tool as a lever to just slightly lift one side of the module at the screw lug A strong (e.g. metallic) tool may be needed for this, and can be used without getting close to any circuitry if applied at the side of the module near the edge of the case. Once the edge of the module is lifted, the module can be easily removed with your fingers. Just be careful to not grab the ribbon cable.



Replacing a module is slightly different. First, note that your module has some metallic tape on the underside. Do not remove this tape because it's purpose is to conduct heat from the metal CMOS back plate to the metal module housing which then helps cool the CMOS imager. But do look to be sure the tape is aligned on the module and does not have any creases or folds that can keep the module from seating fully in the case.


Next, with the locking tab lifted, gently insert the ribbon cable into the circuit board connector, making sure it is fully inserted. It's a snug fit and needs to be inserted straight with maybe a slight side-to-side rocking motion. DO NOT force it. When in place, close the locking tab to secure the ribbon.


Now position the module over it's seat in the case, allowing the ribbon cable to bend naturally. DO NOT force a sharp bend in it. When in place, push the module into the case slot by pressing on the side lugs. DO NOT press on the ribbon cable area on top of the module. It's a very snug fit, and a slight rocking side-to-side rocking motion may be needed. Make sure the lens is centered in the case opening and replace the case bottom.


4. Refocusing or Replacing the Lens in the CMOS module

This is now an easy task. The threaded lens is secured in the module with a tiny set screw which requires a 1mm (I think) Allen hex wrench to loosen.


To refocus the lens, simply remove the case bottom, mark the initial position of the lens with a thin line of paint across the lens threads and module base (optional-for future reference only), then loosen the set screw until the lens can be rotated in the housing. When facing the front of the lens, turning it to the left will move it further away from the CMOS and move the prime focus closer to the camera. The reverse will do the opposite. The lens should turn easily once the set screw is loosened enough, but there are small notches in the lens front rim to aid in turning the lens if needed. There should be enough room in the case to make moderate focusing adjustments without having to remove the module or circuit board from the case. Focusing can be done in web cam mode while viewing the image on a monitor, or by trial and error still or video shots noting the lens position for each and comparing afterwards. Its been claimed that still images of the same scene will have the largest file size when the camera is in best focus, though I prefer a visual indicator and have not tried to confirm this. The standard lens has a large depth of field, and images should appear as sharp as the lens is capable of from about 2 ft. out to infinity when in good focus. When the lens is focused to your requirements, simply re-tighten the set screw and replace the case bottom.

To completely replace the lens, you will need to remove the module from the case (see item 3., above) to allow enough room to completely unscrew the lens from the module. NOTE: If the lens appears to "jam" and not unscrew easily, see this post for a possible reason and solution. Then replace the lens, reseat the module, and replace the case bottom.
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Last edited by Tom Frank; Jun 23, 2015 at 11:18 AM. Reason: Added "last ditch" fix (oven solder reflow) to FAQ list
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