Sonics E-Series - Manual (Page 11)

17) Check the tuning cap (C13A) on the main board using a multimeter on the capacitance setting. They should
read the following based on the frequency of the power supply (check the label on the back of the power supply
for frequency):
15kHz 112 nanofarads If not, replace both C13A (Part No. 817-00161) and C13B (Part No. 817-00162).
20kHz .066 nanofarads If not, replace both C13A (Part No. 817-00090) and C13B (Part No. 817-00090)
40kHz .033 nanofarads If not, replace C13A or C13B (depending on where the cap is installed) with Part
No. 817-00090
18) Check the resistors R26, R30, and R31 using a multimeter on the resistance setting. In order to measure
these, the relay K2 must be removed from the socket as shown below. Push the relay clips back and pull the
relay up.