2. Service
Assembly/Module Diagnostic Trees (Diagnostic Section 3)
100
3.4.2.1 A19 10-MHz Output Test
1 Disconnect cable from A19 output connector.
2 Connect A19 output connector to a scope with 50 input impedance (If the
scope doesn't have a 50 input, use the high impedance input with a 50
coaxial feedthrough terminator installed at the scope end of the coax).
3 Verify presence of a 10-MHz undistorted sine wave with at least
1 Vp-p amplitude.
QUESTION: Does the scope show a 10-MHz undistorted sine wave
with at least 1 Vp-p amplitude?
If Yes: Remove power, replace cable between A9J2 and A10J5,
and retest.
If No: Go to, 3.9.1.1 (A19 trouble tree).
3.4.3.0 A9 80-MHz Signal Test
1 Connect A9J2 to the 50 input of a scope using coax. (If a 50 input is
absent, use the high impedance input with a 50 coaxial feedthrough
terminator at the scope end of the coax).
2 Verify presence of an 80-MHz undistorted sine wave with at least
0.6 Vp-p amplitude.
3 Repeat steps 1 and 2 for A9J3 and A9J4
QUESTION: Does the scope show an 80-MHz. undistorted sine wave
with at least 0.6 Vp-p amplitude present at all three test
connections?
If Yes: Go to, 3.4.4.0.
If No: Remove power, replace A9, and retest.
3.4.4.0 A9 J1 320-MHz Signal Test
1 Adjust input attenuation on spectrum analyzer for a +30 dBm maximum
signal.
2 Connect A9J1 to the spectrum analyzer using coax.
3 Verify presence of a 320-MHz signal of at least +18 dBm amplitude.
QUESTION: Does the analyzer show a 320-MHz signal of at least
+18 dBm amplitude?
If Yes: Go to, 3.4.5.0.
If No: Remove power, replace A9, and retest.
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