This is one of the more cosmetic TZ add-ons that I decided to purchase: while there are a wide variety of "toys" you can add to a Twilight Zone, I really wanted to stay away from them as much as possible. I wanted the machine to look as close to "stock" as possible — while I definitely wanted to improve the appearance and functionality of my TZ, I didn't want it to look like I had raided my son's toy chest.
The "Piano" mod from Pinball Pro is as close as I got to adding "toys" to my Twilight Zone. The piano is a custom-molded plastic player piano, designed to mount under the clock and right over the "piano" shot on the playfield.
The original "stock" piano shot is pretty nondescript and well camouflaged on a standard TZ playfield: if you didn't notice the 1/4" artwork at the very lip of the piano shot hole, you might have no idea where the piano shot was.
The player piano is sculpted to fit under the clock and sit right over the top of the piano shot hole. As a side benefit, the piano has holes to re-arrange the piano light and jackpot lights, making them much more visible from the player's perspective.
In addition, the piano is designed to overhang the metal lip of the entrance to the hole, helping to prevent damage to the scoop and the balls, and a rubber "song roll" supposedly helps to prevent airballs.
This is one "decorative" Twilight Zone mod that earns its keep with both aesthetic goodness and some unexpected functionality. Pinball Pro sells the piano for $27.95 (+ $4 shipping), a reasonable price for a stylish mod.
The Twilight Zone's clock is both one of its showcase "toys" and simultaneously one of the greatest failure points on this pin. Due to a design mistake, the lamps in the clock are completely enclosed in plastic, creating a killer build-up of heat that not only slowly destroys the optos in the clock, but literally melts the clock's circuit board.
The clock's circuitry was also designed as two separate boards connected via an interconnect, another design flaw that has caused problems due to thermal expansion and contraction. All in all, the clock is a failure just waiting to happen.
So, what to do? Well, aside from the great repair tips offered by "Shaggy and Norm" on This Old Pinball DVD #3, Lost in the Zone, the best defense is a good offense: you should replace the problem boards with a re-engineered board. For my TZ, I went with a replacement board by Rottendog Amusements, which is sold by Marco Specialties.
The Rottendog clock board condenses the two boards used in the original design into a single double-sided board, and replaces the hot #86 bulbs used on the original board with ultrabright white LEDs. By removing the two main sources of failure (the hot incandescent bulbs and the interconnect), this replacement board should be much more reliable (plus, with an estimated LED life of 100,000 hours, you won't be changing any more bulbs inside the clock!)
There is another clock replacement board on the market, sold by The Pinball Lizard. I chose the Rottendog board because it was a single-board design (the PinLiz design is two boards like the original) and the Rottendog version was $40 cheaper ($80 vs. $120). The other main difference is that the Pinball Lizard board uses SMT (surface mount) LEDS instead of the generic ultrabright LED's used by the Rottendog board.
Comparing the original board to the new board you can see the simplicity in the Rottendog design (remember, from an engineer's viewpoint simpler is always better!)
Installation was relatively straightforward, at least by TZ clock standards: you need to disassemble nearly the entire clock to replace the board, and that disassembly is an involved affair with some very small parts. Luckily, everything went smoothly, and it only took a few minutes to reassemble the clock with the new board installed.