5 Troubleshooting
112 Model N6705 Service Guide
Bias PCA Troubleshooting
Troubleshooting the bias board involves checking for the presence of the
correct bias voltages on the board. Refer to the following table and
figures.
Note that if the bias voltages at test points 2 - 4 in the following table
are not present, it could be caused by a defect in the power module or
interface board that is pulling the bias voltage low.
TP 1
+ RED
+48 V
Output of bulk supply. If not present, replace the bulk
supply.
TP 2
+ C4
+12 V
If biases at TP 2, TP 3, or TP 4 are not present,
disconnect the backplane and interface board cable
assemblies and recheck. If biases are still not present,
replace the bias board.
TP 3
U9 - 2
+5 V
Same as above.
TP 4
+ C3
+3.3 V
Same as above.
Common
− BLK
Common
Figure 5-2. Bias Board Test Points
To Next Page
Loading...
