Peter,
I have never seen a diagram of the CB cable. The cable tube is straightforward, from the sheave block at the hull, through two turning blocks to the end of the tube just below the sink counter top (about 18 inches above the water line). There are no "windows" to inspect the line. It is not uncommon for it to be hard to raise the last foot or so of cable as the angle of the CB is very steep at that point. I leave the board down about a foot just to keep from having to crank so hard and that also reduces some of the turbulence in the CB slot.
I inspect the cable at each bottom job but have never found any wear. At 18 years I replaced the cable and it looked like new. That was 14 years ago. If you do replace the cable make sure there is a proper back splice at the connection point. Bronze swages will not last on a SS cable in salt water.
Several people have had problems with the encapsulated sheaves freezing in the case. This will obviously make the CB difficult to raise. In most of these cases the unions in the tube are also frozen due to age and as a result most of the tubing must be replaced, making the job that much more labor intensive. Hopefully you are not faced with that problem.
So, if the difficulty in cranking up the CB is only for the last 12 to 18 inches, I would keep sailing and leave the board down a bit. Or but an old Hinckley. They had an electric motor and worm gear to raise and lower the board. And when that quit you quickly learned why they are so expensive to own.
Dave
