my mate x error message 30 unsolved

i have received new cables from mate x support and it did not fix the issue
i have received a new controller from mate x support and it did not fix the issue
they now tell me it may be the battery but my battery works absolutely fine
and they tell me it may be the display but the display sure is not the problem it only shows that there is an error
i am waiting since 1 year to have it fixed now