How to remove the head of a Williams System 11 pinball machine

There are 2 types of System 11 games. Early games (like Pin*Bot, Road Kings) are easy. Even thought the backbox folds down on hinges, the system is the same as the older Williams games (system 6 to 9). This is explained below.

From Banzai Run on, Williams used an 'interconnect board'. This is a small pcb at the bottom of the backbox which just has a lot of connector pins on it. Most wires coming from the cabinet and backbox go to this board. However there are also a few wires which go to other pcb's. So if you're dealing with this type game, label each connector ! And when you start to assemble it, don't start with the first connector you get your hands on, but think first which ones you have to do first.. it's best to start with wires which go to the boards at the top of the backbox and to the wires at the bottom later, so you don't mess them up or have to remove wires to run another behind them.
This kind of games (except for Banzai Run) usually has the new cabinet style which is the same as WPC games.

Note: this is only a guide, I am not responsible in case you mess something up !
Also take care when the cables are disconnected, they easily get stuck behind something (ie a ramp on the playfield).
Take them all together and lay them somewhere they're not in the way for what you're going to do (ie when you're lifting the playfield out of the cabinet, try to put the cables on the playfield, or already out of the cabinet, and on the side of the cabinet where you want to move the playfield to. You don't want to hold the playfield in the air and notice on cable is stuck or still connected !

Here's an image of the backbox.. all these connectors look impressive, don't they ? Well, the people at Williams were smart enough to find a better solution to remove a backbox/playfield. So don't bother about all these connectors (I wish they had been that smart when they designed WPC games :-)

Remove the pinballs from the game ! (Road Kings needs 2 pinballs)
Now lift the playfield 1/3rd up so you are able to see the back of the cabinet.

Pull a bit on the cables that are going down, and you'll notice they all have connectors !

Note there are some connectors in the wiring loom inside the cabinet where it leaves the transfo. So it's also possible to disconnect some wires here instead of in the backbox.

Just unplug all these connectors

You could label them, but there's no real nead for it as they have different colors and sizes.
Note that on earlier Williams games (system 6 to 9) both connectors DO have the same layout and can be switched around. To make matters worse, sometimes they were assembled wrong and a white connecter has to fit a black one. So if you assemble an older game, always double check that the color of the wires matches on each connector.

There aren't that many connectors, and if you just double check what color the wires have, you really shouldn't be able to make mistakes when you'll connect them again.

Of course it couldn't be as easy as this, there has to be one exception. :-(

The exception is one grey cable which you have to remove at the top left corner in the backbox. (On older games the sound board is at the right side.)
Just unplug it, and drop the cable into the cabinet.

NOTE: in the pictures I forgot the grey metal ground wire. You also need to disconnect this (at the bottom of backbox). Don't forget to put it back when you assemble the game !

Now you are able to remove the backbox. Fold down the backbox. You may need to remove 2 large bolts at the bottom of the backbox which secure it to the cabinet (on my machine they were missing, which makes the head 'shake' a bit when I was playing), and 2 other screws in the back of the machine (they are at the end of the metal plates that stick out).

Take all cables out of the hole which goes into the cabinet. Remove 4 screws (marked with blue arrows) and the backbox is loose. Be careful as it may slide down ! It's best to put it away with the help of another person !

Now you are able to lift the playfield out. Check the cables you've disconnected, so they are not stuck behind something !
You'll probably need another person to do this, each on one side of the cabinet. Lift the playfield straight up, and you can take it out of the cabinet.
Btw take care about the row of light bulbs at the back of the playfield, it is easy to bend them so they short against something (as I found out).

Now all you have is an empty cabinet. The weight is not that much, so it's easy to move it. You can remove the legs too.

Assembling is just the reverse way. Put the cabinet somewhere, put the legs on it. Insert the playfield (take care that it's exactly where it has to be as it has to fit in a hinge !) Put the backbox on top of the cabinet. Connect the 4 screws to hold the backbox. The cables from the backbox have to go through the hole into the cabinet, the gray cable has to go up into the cabinet. Then lift the backbox up. Secure the backbox to the cabinet with the large bolts and 2 screws in the back. Connect all cables at the end of the cabinet, going to the backbox. Don't forget the grey cable which you have to connect inside the backbox. Double check you haven't forgotten a cable ! Insert pinballs, put the playfield glass on and you're done !