I would just make sure that you get good clean connections on the pins - those plugs are a swine to solder, make sure the solder is fluxed else the wires won't hold.
The connections I would use are
pin 1 Red
pin 2 Green
pin 3 Blue
pin 6 Red Ground
pin 7 Green Ground
pin 8 Blue Ground
pin 10 Sync Ground
pin 13 H-Sync
pin 14 V-Sync
This should be enough to get the picture on the screen. On both the male and female ends you will notice that pins are marked differentlly. Looking from the back of both - pin one is on the left handside whilst on one whilst on the other, pin 1 is on the right.
If you are going to build the cable yourself then I would write the colour in the cable and which pins that you assign them to, this will make life easier.
If the hood is made of metal then most cables the outer screen is used as your earth this can be soldered onto the inside of the metal hood.
Or it is soldered to the outer metal rim of the plug above the pins ( this wire is then inside the hood )
You may be able to purchase a ready made lead that has is already wired up that has a plastic hood that is bolted together, then all you have to do is to remove the hood and check for the +5v pin 9 and desolder the wire.
I would then insulate any desoldered wires from each other, as to avoid any short.
If you get the H-Sync and V-sync wires crossed at one end then you won't get a picture.
Warning
If your cable does not work then disconnect it from your monitor and MAC before making any alterations - heat from your soldering iron can damage your equipment.
Make the changes needed then test the cable again.
I take no responsibility here for your ability to use a soldering iron and for making up cables - their are companies out there that will make cables up for you. Or like I wrote a bit back, get a ready made cable that can be modified. But test the cable first to see if it needs modifying.
I hope that this solves the problem.
