How to open a pinball machine--This is important if you've never seen it done.
Opening the Backbox or Head
If you have an electromechanical, the back door opens with a lock. If you
don't have the key then drill out the lock. You may have a key to the lock
on the back door key hook on the inside of the coin door, or just inside the
door. I hate drilling out a lock if I don't have to.
On a solid state the front of the head opens, sometimes with a hinged frame,
or sometimes turning the key on the top or side will release the glass so it
can be lifted up and then out. Behind the glass is usually a door which
hides all the brains of the machine.
Opening the Main Cabinet or Body
First you must open the coin door. If you don't have the key, just drill
out the lock. Prying the door just damages the cabinet and door. At this
point some machines are different. Most manufacturers including Gottlieb
and Williams have a latch close to the center or upper right over the coin
door. Move this latch to the left and it will release the playfield glass
lockdown bar, which then can be removed by lifting straight up. The
playfield glass will then slide out the front of the machine. On most
Ballys the latch is on the right side of the coin door opening. Lift that
latch to the left. On Ballys from the mid-70s on, the latch will release
the playfield glass lockdown bar and the glass can be removed like Gottlieb
and Williams. On earlier Ballys the latch releases the playfield
glass/lockdown bar/frame assembly which will lift up and hinge at the back.
You can either lift the frame towards the front of the machine and away, or
just tilt it up and use the underlaying prop sticks to hold the glass frame
At this point most playfields can be lifted up by grabbing at the outhole
area and pulling up. Some 60s Gottliebs have a release bar under the
playfield that must be pulled while the playfield is being lifted. Many
woodrail, pre-60s, machines will have to have long screws on each side of
the playfield removed before the playfield can be lifted. A few machines in
the early 1960s had other clamps or devices to secure the playfield down.