8 Troubleshooting Only manufacturing firm and authorized service workshops may work on the Laboratory- Vacuum-System and their accessories during the warranty period. 8 Troubleshooting Only manufacturing firm and authorized service workshops may work on the Laboratory- Vacuum-System and their accessories during the warranty period. Vacuum pump does not start Vacuum pump does not generate a vacuum or only an inadequate one Running noise Glass components Cable(s) No pressure indicated on the controller Controller cannot be set or programmed Missing control signal