Comtech EF Data EQ90 Series - Manual (Page 53)

Maintenance EQ90 Amplitude Equalizer
4–2 Rev. 2
4. Set the BYPASS/LVL MON switch (8, Figure 3-3) to the LVL MON position
and verify that the front panel STATUS indicator lights green.
5. Remove the A IN signal input to the equalizer and observe that STATUS
indicator lights (red).
6. Disconnect the signal source and termination cables.
7. Reconnect the system cables to the equalizer assembly.
4.2 Troubleshooting
The troubleshooting procedures listed in Table 4-1 is designed to aid service personnel in
locating faulty assemblies and components in the equalizer. The troubleshooting
procedure lists the symptoms that could be detected during the checkout procedure and
operation and the probable causes for each symptom. The last column of the procedure
gives the corrective action required to isolate and correct the malfunction. When it is
necessary to replace and assembly or component, refer to the replacement procedures of
Paragraph 4.6.
Table 4-1. Equalizer Troubleshooting Procedure
Symptom Probable cause Corrective Action
Front panel STATUS indicator out 1. No power applied to unit. 1. Check that primary AC power is applied to rear
panel power receptacle.
2. Fuse. 2. Check fuse. Replace if open.
3. Power Supply 3 Check for +12 VDC at the output of the power
supply. If +12 VDC is not present, replace
power supply.
STATUS LED lights red 1. Power Supply 1a Refer to DC interconnect diagram and ensure
+5 and -5 VDC is present at connectors J4, pin
3 and 5.
1b If voltage is not present, replace power supply
assembly.
2. Equalizer 2a Measure the output power level of the
equalizer; the peak or continuous wave output
power level shall be above -20 dBm.
2b If the power levels are correct and below
-20 dBm, set the LVL MON switch on the
equalizer module to the BYPASS position.