If no peaks are present, and the MSD does not pass tune, the next step in the troubleshooting process is to determine whether the problem is related to the electron multiplier and its electronics or not.
Use the manual tune program to initiate a repeat profile scan.
Increase the electron multiplier voltage.
If the abundance of the noise increases, the problem is probably not related to the electron multiplier or its electronics. If the abundance of the noise does not increase, the problem is probably in the electron multiplier or related electronics.