PinballZone.com - Twilight Zone by Bally


Top of the Twilight Zone playfield. The clock was removed in this picture.	Bottom of the Twilight Zone playfield.


The corner of the playfield that contains the Gumball Machine.	The Piano are of the playfield. Clock was removed in this picture.


Twilight Zone - Full Playfield View	The Twilight Zone Power Mini-Playfield (Magnetic Flippers)

My own Clock Mod. When tightening the top right screw (when looking at the back of the clock), you risk stripping the plastic screw hole. It is difficult to get the screw tight enough to hold up the metal piece, but not strip the plastic hole. Unfortunately, if this metal piece sags, it hangs into the ball path on the Power Ramp, creating a ball jam. If the metal bracket is not there, it creates the potential for the ball to hop off of the Power Ramp, and jam behind the clock. To prevent this entire scenario, I installed a hair-pin that I snipped to the correct size around both the plastic back of the clock and the metal bracket. When installed as shown, the screw can be left slightly lose, and not affect the bracket in the least!

The properly installed Clock PCB mod. The clock originally had Zero-Ohm Jumpers installed at locations D1, D2, D3, and D4. In an effort to prevent heat build-up, it is commonly recommended to replace these jumpers with diodes to allow the lights in the clock to only light on half of the AC wave. This effectively dims the lights, but also makes them generate less heat. Heat is the factor that causes the most problems with the clock PCB's. To slightly alleviate the diodes causing the lights to dim, you can install two of the diodes (D1 and D4) according to the screening on the PCB, and two backwards (D2 and D3) with respect to the screening on the PCB. This will alternate the top left and bottom right with the top right and bottom left lights on the opposite sides of the AC wave. Basically reducing the dimming effect of installing the diodes, while still lessening the heat build-up. Don't forget to drill holes in the top and bottom of the casing of the clock to allow more airflow. I will post pictures of the proper hole configuration soon.