Thank you very much for the replies. I havent had time for the machine since i am away most of the time during the holidays. I will work on the problem next week and see if i could resolve the issue. I did have 5 minutes to check the voltage on the drives and this is what it shows (i could set only voltage info, very confusely translated servo manual) :

https://i.imgur.com/OhkgXSr.jpg

I see lots of voltage deviations, could this be an issue?