I have just bought a used MAHO MH500C. I have a problem with the spindle. The machine didnt start when I press the start button. In the LED error screen there is the code 30. I have the electrical drawings of the machine and I checked the cables. This error is caused by Indramat TRK6 spindle drive. I checked also the TRK6 and I have found that the problem is d1 relay that when it is triggered the green LED "BB" goes on. The relay is ok but I cant found what is the problem. Do you have any suggestions or how can I find the manual for Indramat TRK6-4U?