Troubleshooting
6-13 Troubleshooting Test – 3739B/C A1 Bias Control PCB DC Bias Check
VectorStar ME7838 Series MM
PN: 10410-00306 Rev. F
6-17
6-13 Troubleshooting Test – 3739B/C A1 Bias Control PCB DC Bias Check
This procedure verifies that the expected DC Bias voltages of RF components and fan assembly are present on
the A1 Bias Control PCB located on the 3739B/C Test Set chassis.
Equipment Required
•
Digital Multimeter
Procedure
1.
Turn off the 3739B/C Test Set and unplug the AC power cord.
2.
Remove the top cover of the 3739B/C Test Set.
3.
Remove the stiffener plate.
4.
Unplug the cable harnesses connected to the connectors listed in
5.
Connect the Test Set to AC power and turn the unit back on.
6.
Use a digital multimeter to measure the DC voltages presented at the connectors per. Refer to
for connector locations.
7.
If any of the voltage is not present, replace the A1 Bias Control PCB Assembly.
Table 6-6.
RF Component/Fan Bias Voltage Check
Connector
Function
Common (Pin)
Measure (Pin)
Expected DC
Voltage
P1, P2 & P3
RF Input Amp Bias
3
2
2.2 V
3
1
6 V
P5
SPDT Bias
1
3
11 V
1
4
11 V
1
5
5 V
1
6
5 V
P9
Fan Bias
2
3
12 V
P15 & P16
Doubler Module
2
4
11 V
2
5
8 V
2
6
6 V
2
8
5 V
2
12
5 V
2
14
5 V
Summary of Contents for VectorStar ME7838 Series
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