Symmetricom 5071A, Сборка и сервисное обслуживание

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2. Service
Top-Level Diagnostic Tree (Diagnostic Section 1)
48
If TEST 9, 87 MHz PLL test (<num.> kHz, <num.> V), Go to, A5 87 MHz
PLL tree (3.2.1.0).
If TEST 10, 9.2 GHz PLL test (<num.> V), Go to, Rf-chain tree (2.3.1.0).
If TEST 11, Servo register test, Remove power, replace A6, and retest.
If TEST 12, Servo converter timeout test, Remove power, replace A6, and
retest.
If TEST 15, Pps register test, Remove power, replace A8, and retest.
If TEST 16, Pps interrupt test, Go to, 1.2.2.
If TEST 17, Power logic signals test, Remove power, replace A11, and
retest.
*Failure of test 14 may occur with any combination of tests 2, 3,4,5,9, and 10.
1.2.2 Pps Interrupt-Error Test
1 Install the short-extender board (part number 05071-60051) into
the spare slot on the A1 motherboard.
2 Use an oscilloscope with trigger level set to +1.5 volts (no auto
trigger) and high-impedance probe to check presence of 20
μ
s
pulses with an amplitude greater than 4 V at a rate of 1 pulse per
second on XOPTJ1 pin 44.
QUESTION: Is the waveform correct?
If Yes: Remove power, replace A3, and retest.
(If the problem persists: remove power, replace A1, and retest;
or contact Symmetricom for further assistance.)
If No: Remove power, replace A8, and retest.