Specifications

General Maintenance 4
5975 Series MSD Troubleshooting and Maintenance Manual 159
To adjust the quad frequency
Materials needed
• Screwdriver, flat-blade, large (8730-0002)
Procedure
1 Make sure the MSD is at thermal equilibrium. It takes at least 2 hours
after all heated zones have reached their setpoints for the MSD to reach
thermal equilibrium.
2 Open the analyzer cover.
3 Make sure the RF cover on the side board is secure and no screws are
missing. A loose RF cover or missing screw can significantly affect coil
adjustment.
4 In the Tune and Vacuum Control view, select Optimize Quadrupole Frequency
from the Execute menu.
5 Enter an m/z value of 100.
6 Slowly turn the quad frequency adjustment screws to minimize the voltage
displayed (Figure 29).
Turn the adjustment screws alternately. Turn each screw only a little bit at
a time. Keep the screws at equal extension. The minimum voltage is
typically between 50 and 70 mV.
7 When the voltage is minimized, click Stop.
WARNING
Do not remove any other covers. Dangerous voltages are present under these
covers.

CAUTION
Do not use a coin to adjust the screws. If you drop it, it could fall into the electronics
fan and cause significant damage.