Symmetricom 5071A - A10 Diagnostic Tree (A;M Subsection 5)

2. Service
Assembly/Module Diagnostic Trees (Diagnostic Section 3)
101
A10 Diagnostic Tree
(A/M Subsection 5)
This subsection describes the A10 Output Frequency Distribution Amplifier
Module diagnostic tree.
3.5.1.0 A10 Module Power Checks
1 Check the +12V and +5V terminals on A10 with a DMM and verify +12V is
between +12 and +12.5V to chassis.
2 Verify +5V is between 5.25 and 5.5V to chassis.
QUESTION: Are power-supply voltages correct?
If Yes: Go to, 3.5.2.0.
If No: Remove power, replace A10, and retest.
3.5.2.0 A10 Module J5 80-MHz Input Test
1 Disconnect cable from A10J5.
2 Connect free end of the cable to a scope with 50  input impedance
(If a 50  input is absent, use the high impedance input with a 50  coaxial
feedthrough terminator at the scope end of the coax.).
3 Verify presence of an 80-MHz undistorted sine wave with at least
0.6 Vp-p amplitude.
4 Reconnect cable to A10J5.
QUESTION: Does the scope show an 80-MHz undistorted sine wave
with at least 0.6 Vp-p amplitude?
If Yes: Go to, 3.5.3.0.
If No: Go to, 3.5.2.1.