Agilent Technologies E8285A Manual page 72

Troubleshooting
Manual Troubleshooting Procedures
Verify Test Set's Reference Path
Out-of-Lock (OOL) LEDs
Out-of-lock (OOL) LEDs light when a phase-locked loop inside an assembly is
failing. The signal generator synthesizer and the receiver synthesizer assemblies
have these LEDs mounted close to the top of the modules. The location of each
LED is labeled on the assembly.
Verify that the CDMA generator reference and the reference are working before
troubleshooting the receiver synthesizer and/or the signal generator synthesizer
assemblies.
Figure 2-18 Out-of-lock LEDs
SIG GEN SYNTH
Out-of-lock LEDS
RCVR SYNTH
CDMA Generator Reference Assembly Verification
1. Turn the Test Set off and remove the external cover.
2. Remove the bottom cover and verify that the cable is connected between the
3. Turn the Test Set on and verify that a 10 MHz signal is present on J15 of the
4. Remove the Reference assembly.
5. Turn the Test Set on and verify that a 10 MHz signal is present on pin 20 of J63
72
S:\agilent\e8285\ALR\Book\chapters\trouble.fm
EXT REF IN connector and J17 on the CDMA Generator Reference assembly.
CDMA Generator Reference assembly.
If no signal or a poor signal appears at this connector, then the CDMA
Generator Reference assembly is faulty.
and pin 19 of J18. This is the reference signal from the CDMA Generator
Reference assembly.
DS3 DS4
DS2 DS1