Disassembly

See the NAV200 gallery for photos of the inside of this sensor. Wiring details are shown. Be very careful when disassembling and reassembling the sensor as the wiring is poorly designed, with some wires being too short to allow much movement of the optical assembly while other wires are excessively long. Some connectors even have had wires installed and then cut off. This is normal.

Observe standard precautions to prevent electrostatic discharge.

Remove the metal ring around the head (three philips screws) and the socket cap screws under it. Don't bother removing the top plate as in this photo as it won't get you anywhere.

Remove the four screws in the corners of the bottom plate. The top shell is now removable, but it will likely be stuck in place by a gasket. Tap the top shell to loosen the gasket.

If you aren't going to use the sealed circular connectors (their mates are not cheap), you will need to remove them. This requires removing the optical assembly and the bottom circuit board.

There is a thin black fiber optic cable going from the laser box to the side of the optical assembly. Be careful with this as it will be extremely hard to replace. Don't allow it to bend sharply. You can see where it enters the optical assembly here. It is epoxied in place on both ends. Do not remove any screws attaching optical components as these are likely alignment-crticial.

Remove the two screws attaching the logic board to the optical assembly. Slide the logic board straight up, being careful not to jerk the fiber optic cable behind it (it will probably catch on the capacitors on the back of the board - a little bending is OK). Remove the logic board. You now have access to some of the wires under the optical assembly. Unplug these, noting their original positions. It may be helpful to mark some connectors with a marker to show their original positions.

Remove the four screws in the center of the bottom plate. Carefully hold the optical assembly in place, as it will be retained only by the remaining circuit board after these screws are removed.

Unplug the optical assembly and the remaining wires. You will have to hold it at inconvenient angles to get all the wires out.

The bottom board is attached by two screws on each card-edge connector. Remove these and unplug the wires from the circular connectors. You can now remove the bottom board.

Unscrew the round nuts on the circular connectors. These have narrow notches, and can be turned with the pegs on a c-clip tool. Remove the connectors but keep them around. You will reuse the wire and header sockets for the USB interface.

Now reassemble the whole thing. Keep a close eye on all the wires under the optical assembly. Be careful not to crush any wires where the bottom of the optical assembly touches the bottom plate. The two APD power connectors (six pins with one wire cut off) are identical and wired identically on the bottom board. The position of the other connectors is important.

Be aware that there is a 2-pin connector on a 5-pin header (see this image). Its position on this header is important.

It is possible to plug in and remove the 8-pin connector for the INMOS link without removing the logic board. I recommend using a small flathead screwdriver. Use the screwdriver to pry up the ends of the connector and to push it back down. Push on the connector, not the wires.