Does anyone know of a step-by-step guide to testing, troubleshooting and repairing these displays? I know Pinwiki has info on them but its not exactly an easy 'guide' on how to fix them. Its more of a lesson of sorts and its kind of hard to follow. I would love to learn this process and repair technique. If there isn't one, maybe someone can offer to post one?? Would be awesome!

Thanks for all the info. I think some of the diagnosis steps are just basically needed. Like if a digit is always off, the 100K resistor is probably bad, but it went bad because the level shifter was bad. So its like a cascade effect. All great info and thanks so much, looking forward to learning more about general repair of these displays.