I have been working with these cameras a bit and have seen some of the mistakes people can make so I thought I would share some learnings. I have only worked with W80 and W150 cameras but I think this information will be valid for all of the Sony W series.
WATCH OUT FOR THE FLASH VOLTAGE!!!! It gives a nice tingle!
1. Most, if not all, of the ribbon cables (wide brownish/yellow cables) have a release mechanism holding them together. While it is fairly easy to remove the cable, it can be a pain to reinsert it without releasing the latch. Look for a sliding piece of plastic on the connector with a magnifier. This will help keep the ribbon cables from getting dinged up.
2. The only time you should need your soldering iron is to connect up the three 30 guage wires. To take the camera apart you do not need the soldering iron.
3. When soldering the wires on, be careful that you do not solder to the metal part of the button. The metal around the buttons is ground and if you short the red wire to it, the camera will not work. Make sure you can see clearly where to solder before you solder. Use a magnifier! And I suggest buying 30 gauge wire strippers. Using wire cutters will damage the wire and just a couple bends will result in a broken wire.
4. Locate the assembly/disassembly instructions on the yeticam site for the camera you are working on and use them. Learn from what someone has done before. The only thing bad about making a mistake is not learning from it that's why I am sharing these learnings.
5. The way I have located the fresnel lens on my two cameras is this. Find the mechanical drawing on the yeticam site. Print it out and make sure the print out is the same size as the control board. Tape it on the back of the case and drill the 4 mounting holes through the back of the case. Then I use a small bit (1/8") and drill the PIR sensor hole thru the back and the front case. This gives a pilot hole to drill the lens hole bigger on the front case. Then when I want to glue in the lense, I remove the control board and shine a laser pointer through the hole in back and move the fresnel lens until the laser light dot is centered on FOCUS point of the fresnel lens. The focus point of the wide-angle fresnel lens is NOT the center of it. Once that is done, just fill the hole in the back of the case with hot melt glue of the bondo glass.
6. There is a wealth of information about problems encountered when doing these cameras on this site. Search through and read it even if you aren't having the exact problem. The more you learn about these cameras, the more easily you can find a solution to your problem.
7. Once you have completed and tested your camera, give MUCH thought to camera placement. It is very frustrating to wait a week or more after placement and find out that the deer in the area do not use qtips. I have pictures that appear to be false triggers but have not actually had a false trigger yet. I have seen too many deer ear canals. So I carry a spare camera with me and use it to judge what the trailcamera is going to see. These are great cameras but the results are no better than your camera placement.
8. If you get a picture of Bigfoot, make sure to copyright it quick. It might be worth some money. Ok, just checking to see if you read this far. I will add more as I think of things.