Symmetricom 5071A - A15 Diagnostic Tree (A;M Subsection 6)

2. Service
Assembly/Module Diagnostic Trees (Diagnostic Section 3)
107
A15 Diagnostic Tree
(A/M Subsection 6)
This subsection describes the A15 9.2 GHz Microwave Generator Module
diagnostic tree.
3.6.1.0 A15 Module Power Check
1 Check the +4.5V terminal on A15 with a DMM.
2 Verify +4.5V is between +4.4 and +4.6V to chassis.
QUESTION: Is the power-supply voltage correct?
If Yes: Go to, 3.6.2.0.
If No: Go to, 3.6.1.1.
3.6.1.1 A18J3 Voltage Test
1 Disconnect cable from A18J3.
2 Connect a DMM set for dc volts to A18J3.
3 Verify the voltage present between +4.4 and +4.6V.
QUESTION: Is the voltage between +4.4 and +4.6V?
If Yes: Go to, 3.6.1.2.
If No: Go to, 3.8.1.0 (A18 diagnostic tree).
3.6.1.2 +4.5V Cable Test
1 Remove instrument power.
2 Unsolder wire from A15 +4.5V terminal.
3 Reapply instrument power.
4 Check voltage on the wire with a DMM.
5 Verify that the voltage is between +4.4V and +4.6V.
QUESTION: Is the voltage between +4.4V and +4.6V?
If Yes: Remove power, replace A15, and retest.
If No: Remove power, replace cable, and retest.