Re: looking a a swiss machine citizen l20 type VII
I can only answer a couple questions, but Ill answer what I can.
You can see if it has a full C axis if its under power. In MDI, just command M18C90.5 (or choose any number with a decimal. If its an indexer only it will only go to 1,5, or 15* increments depending on the indexer, no decimal will be accepted. )
Old machines have lots of issues, but few present themselves before the moment of failure. Electrical problems are common in old machines, servo amps or drives going out, buttons on the control not working well, wiring problems... You could bring along an indicator and see if there's backlash in the ball screws.
As for learning to program, Citizen offers classes for free at all their distributors a few times a year you can see the schedule here .
Going to one of those is your best option. Up here in MN, 2 technical colleges teach Citizen programming in a class once a year. Existing programs are always an easy way to learn code sequencing, so request a couple dummy programs from the company. I believe the control is a mitsubishi, but Im not 100% sure. I have some training materials I could send you if you PM me too.
CNC Product Manager / Training Consultant