Honeywell Chadwick-Helmuth 8500C Maintenance Manual page 84

Chapter 5 - Maintenance And Repair
Table 5-10. 8500C/C+ Balancer/Analyzer Calibration Tests
Problem
5.5.1.5.1 500 Hz Anti-Aliasing (cont'd.)
Signal aliasing above 0.005 IPS remains on
display
5.5.1.5.2 10 kHz Anti-Aliasing
Signal aliasing above 0.005 IPS remains on
display.
5.5.4 8500C/C+ Spectrum Accuracy Test
True amplitude which was calculated for a
harmonic peak does not fall between minimum
and maximum limits in Table 5.4a or 5.4b.
5-40 Chadwick-Helmuth A Business Unit of Honeywell International, Inc.
Solution
3. If noise is at 500 Hz, it is an aliased signal
most likely caused by analog board.
Replace analog board (Figure 5-17, A2).
1. Check 8500C/C+ harness assembly
(Figure 5-19) for shorted or open
connections which can be caused by loose
or pinched wires, unplugged connectors, or
worn-through insulation.
2. If noise is not at 10 kHz, it is not an aliased
signal: however, the noise and spurious
signals test (Section 5.5.1.4) should be
performed.
3. If noise is at 10 kHz, it is an aliased signal
most likely caused by analog board.
Replace analog board (Figure 5-17 A2).
1. Check all cables for shorts, proper
connections.
2. To isolate whether the 8520C is at fault,
redo Spectrum Accuracy Test without
8520C. To do this, set up equipment in
accordance with Figure 5-11.
3. Check 8500C/C+ harness assembly
(Figure 5-19) for shorted or open
connections which can be caused by loose
or pinched wires, unplugged connectors, or
worn-through insulation.
4. Analog board is most likely at fault.
Replace analog board (Figure 5-17, A2).