I don't know what type of controls you're using, but this error you see may not mean you have to change the servo drive card immediately. First you need to look at it which indicator led on the card shows the error code. Servo card is problematic if 6 shows. But there are problems in the MMC wiring harness if it shows 4 as an example. Cable groups can give this error when there is a problem. Your voltages look normal, but you'll have to look for faults. It also gives this error only for axis 6 or gives it all between 1-6. You need to follow these methods, my opinion.
When you say RJ2, there's still a lot of different controllers. It's hard to describe it that way. The old ones have only one drive card. New type RJ2 some have one card, some have separate module-shaped cards for each engine. It is not only for me to share pictures of the Controller, the cards, and especially the card that gives the error code, but for many people who read the subject will give a better idea.
If you changed the drive card, it looks like your problem is probably in the drive cables. I uploaded a document on the subject to this link. Your examination might help.
