Like others I have some old Bally machines with the plasma displays and considered upgrading them to LEDs but found the cost prohibitive. I stumbled upon this site http://www.baumfalk.net/Displays/bally_en.html and figured I would give it a go. After some minor changes to accommodate different parts and some rerouting I had some boards made and initial results are promising. So although these are limited to one color they are a direct plug in replacement and don't require the high voltage of the plasma displays. Here are some pics of the various stages. I can post more pics if you are interested.

FB_IMG_1552365690611 (resized).jpg

Pecos -

I have built the Pinitech displays (early version - LED) and I really like them. They do not use the high voltage, so I removed the high voltage fuse on the SDB for the machines I have them in since I replaced all the displays in those machines. If high voltage is applied to the retrofit displays, you will burn it up. I followed the instructions and I removed J1 pin 1 from the retrofitted displays so high voltage could not be applied to the retrofit even if I forgot to remove the fuse. I think that by removing J1 Pin 1, you could mix the displays. However, I think the combination would make the displays look weird due to the mismatch.

As far as a single digit out, that's either a burned up resistor or a bad transistor. There's a recommendation out there to switch to 1/2 watt resistors instead of the 1/4 watt resistors originally installed.

For the burned displays, I have moved those to the highest number player, for example player 4 or 6. Most games played are single or double, so I don't think the players are that concerned about displays for a spot not used.

I have not tried Pinitech's new plasma looking displays - but I plan to try them once I find I have a need for a new set of displays.

If you do replace just one display, please let the community know how it looks and how it went.

They should be individually swappable, yes.

I'd put all led on the one on route and save the plasma for home games

Just curious which 7 segment display you chose for your build? Do you have a part # you would be willing to share?

I have a credit display that is shot and replacing all the displays are not in my budget, yet. I can build and fab this for one display quickly. I hate to order a bunch of displays to have to demo the displays. Any info would be appreciated.

I can sell single displays for the Pinitech UNO / TRADITIONAL models. Contact me via PM/email if interested.

Generally plasma displays wear out from use or over-voltage. In the box, they should last a while!

RETROFIT Kits are something I'm only doing on-demand at this point & I'm only selling those as a set (converts 5x plasma displays).

I'd highly recommend the Pinitech UNO DIY Kits in ORANGE however. It's not much more $$ per display & you gain many features over the RETROFIT kits.. adjustable brightness, light block foam, custom digits that look awesome. Incredible value for what the displays achieve.

Pinitech UNO:
https://www.pinitech.com/products/ballystern_display_uno.php

Let me know if you have any additional questions!

---
http://www.pinitech.com - "Pinball Inspired Technology"
NVRAM, Bally/Stern LED Displays & Mods for pinball machines

Wolffpac makes kits. Cheap, easy to build and work great. And all new parts.

https://www.wolffpactech.com/

I've built several:

https://pinside.com/pinball/forum/topic/wolffpac-6-digit-display-kit-review

He also came out with kits for Williams games:

https://pinside.com/pinball/forum/topic/new-display-kits-for-williams-games-review

Sorry, I won't be offering custom digits with the RETROFIT kits. They were spec'd a certain way with the design and materials & I have no plans to revisit the design or "update" them with features of the new displays I'm offering. The costs would go up and as-such the price would have go to up, putting them even closer to the full kit pricing.. when the full kits offer a number of additional benefits.

If you're trying to get out the cheapest way possible, it seems you'll have to find some used plasma displays for replacements or possibly buy a full LED display kit for one machine, and then have the extra plasmas to put in other machines. For LED sets, there are a ton of options these days, but if you're looking for something that will look "stock" when installed in a line-up, or that has the ability to work in the same game with plasmas and blend well, then the new custom digits I've done on the Pinitech UNO / TRADITIONAL displays would be the ticket. You don't have to upgrade EVERY game.. you just upgrade one or two, so you can gain the plasma displays that are freed up for your other games.

---
http://www.pinitech.com - "Pinball Inspired Technology"
NVRAM, Bally/Stern LED Displays & Mods for pinball machines

Also wanted to mention, for you or anyone else..

Through 2019 I'm offering a low-hassle way to try out a single Pinitech UNO / TRADITIONAL display in orange color (assembled only), so people can see how it blends with the original plasma displays. If you buy a single orange display and for whatever reason don't like it, you can return it, no questions asked, for a refund minus any shipping costs within 14 days of receiving the order. Plus, I invite feedback either way on the Pinside thread below.

More Info:
https://pinside.com/pinball/forum/topic/new-pinitech-led-displays-for-classic-bally-stern-plasma-contender#post-4791457

A single display ships fairly cheap First Class Mail. Total cost (both ways) is about $8 total shipping if you do want to return it. That said, I don't really expect to have many people not be impressed by what they see in-person, which is why I'm making this offer

---
http://www.pinitech.com - "Pinball Inspired Technology"
NVRAM, Bally/Stern LED Displays & Mods for pinball machines

As you've found, the original plasma display single sided boards don't put up with a lot of heat on the pads. Seems some pads would lift no matter how careful you were, just from age. When I created the RETROFIT kits I expected half the people to adopt the "parallel resistor" method, which IMO cuts down time significantly and also limits the chance of lifting pads because you're only really fully replacing the driver transistors. Not many people adopted that method though.

You're welcome!

---
http://www.pinitech.com - "Pinball Inspired Technology"
NVRAM, Bally/Stern LED Displays & Mods for pinball machines

I too have used Wolfpack and like what they offered.