User`s guide

3-20 Chapter3
Theory of Operation and Troubleshooting
Troubleshooting
Figure 3-9 Good Port 2 A Channel Response
If there is a power hole or roll off in the response, check the RF cables.
Refer to Figure 3-14, Figure 3-15, or Figure 3-16 for cable locations.
If no response is seen for channel A, check the bias connection to switch
S4 (see Figure 3-13) and the J14 connection (see Figure 3-17) on the test
set interface board. If the bias connector is loose, reconnect it. If the bias
connector is firmly in place in the J14 connector, check the bias voltages
(+0.62 Vdc and +16.3 Vdc) on switch S4. The center bias pin on S4 should
be approximately +22 V.
1. Use the tab on the side of one of the switches (S0, S1, S2) as the
ground connection point.
2. The red wire is the common drive pin and should measure
approximately +22 Vdc.
3. The blue wire is the solenoid drive for pin number one. The voltage on
this pin measures approximately +16.3 Vdc.