This thread is exactly what I've been looking for. I've been working on putting LEDs in my Bally Star Trek. Backbox and GI have been no problem and work fine. It's the controlled lighting in the inserts that I had the flickering problem. I read somewhere else that a 1K resistor across the socket will work so I dug through my box of resistors and found a 470 ohm, a 1.8K, a 3.3K which all worked and stopped the flickering. Also tried a 9.1K and a 22K but they did not work. I guess they had too much resistance.
I've been trying to figure out how and why using a resistor across the socket would work and this thread finally answered my question. Now I understand what's going on with the circuitry on the lamp driver board. Thanks for the explanation!
I've now gone ahead and ordered 100 1K resistors off of ebay. Set me back an entire $1.49 including shipping! Once I get them I'll fire up the old soldering iron and get to work. It will also give me a chance to fix a few of the loose sockets that have been bugging me too.
What I don't get is why the guys like Cointaker don't offer a bulb with the resistor already built in? They offer non ghosting bulbs that have some type of circuit built into the bulb. What is it that they put into a non ghosting bulb anyway? It would seem really easy to put a resistor into an LED and would make it real easy on those that don't feel comfortable in soldering or adding another board to their pin. It would be a great new money maker for the LED sellers also.