Customer Service Center

1. Ensure that the unit has External Power supplied and the unit has been switched on for at least 5 minutes before any replay test commences.
2. Try to playback a file that was supplied with the unit. These ‘Supplied Files’ could include files with the following filenames:-
       - Calibration
       - Calibration 2
       - STR-4500- 140
3. If one file does not playback try all that are available
4. If these file are no longer available use any file that has been known to work in the past….if no known files are available then please refer to FAQ10582
5. Does the front panel display have a green LED and does that screen say that it is playing the file?
6. If step 5 is "true" this is a positive sign. Now check the output. Go to step 8.
7. If step 5 is "false" then it is likely that the file has been deleted or moved
       - Investigate the directory structure through the Webserver or VNC
       - Ensure data is in the home/spirent/data directory. Files typically have sizes >100Mb and often >1Gb.  Check they have a reasonable file size.
8. If the GSS6400 plays back one of the supplied files and signal levels are 40-50 dB then there is NOT a playback problem.
9. If the unit appears to play some (or all) of the supplied files back but there is no GPS fix on the attached receiver or the signal levels are below expected levels:-
       - Check that the Attenuation in the system is set to 0dB. (By default the last attenuation is used).
10. If the unit does NOT play back ANY of the stored files then
        - Check that Power is really supplied by looking on the Power menu.
        - See if an external 10MHz can be supplied on the rear 10MHz input.
11. Do any of the files playback now?
12. If step 11 is "true" then the likelihood is that the OCXO is broken and the unit requires repair. Please contact Spirent Applications Support.
13. If step 11 is "false" confirm the rest of the test set-up external to the GSS6400:-
        - There is not a block between the GSS6400 and the GPS test unit
        - GPS test unit can take the input from the GSS6400

If the above steps do not help, contact Spirent Applications Support detailing all the steps that have been taken.