Honeywell Chadwick-Helmuth 8500C Maintenance Manual page 77

Problem
"ANALOG FILTER FAILURE" (cont'd)
"DISK INCORRECTLY FORMATTED"
8500C/C+ pilot light is not on and screen
display is blank.
NOTE: The backlight may still be
working in this situation.
Table 5-8. Troubleshooting Guide
8500C/C+ Balancer/Analyzer
6. Analog board is most likely at fault.
1. Format a disk several times in disk drive
2. Try formatting another disk.
3. Verify that ribbon cables and disk drive
4. Check 8500C/C+ harness assembly
5. Clean disk drive heads (Section 5.7.1.2,
6. Replace disk drive.
7. Digital board is most likely at fault. Replace
1. Adjust LCD CONTRAST and
2. Check fuse on power supply board A3 in
3. Make sure item (8) on Figure 5-19, Sheet 2,
4. Check 8500C/C+ harness assembly
5. To determine whether one of the 8500C/C+
Solution
NOTE: Intermittent failures are not
likely to be caused by the keypad panel
Replace analog board (Figure 5-17, A2).
NOTE: In the following step, do not
use a chart disk or any other disk with
important data on it because all data
on the disk will be erased.
(for format procedure, see Section 5.7.1.2).
power connection are connected properly.
(Figure 5-19) for shorted or open
connections which can be caused by loose
or pinched wire, unplugged connector, or
worn-through insulation.
"Disk Drive Cleaning Procedure").
digital board (Figure 5-17, A1).
BACKLIGHT ADJ knobs on 8500C/C+. If
screen is still blank and backlight is not
working, verify that unit is receiving power.
accordance with Section 5.7.5, "Fuse
Replacement."
is connected.
(Figure 5-19) for shorted or open
connections which can be caused by loose
or pinched wires, unplugged connectors, or
worn-through insulation.
boards may be causing the problem,
perform the steps shown in the flowchart in
Figure 5-12.
8500C/8500C+ System Maintenance Manual 5-33
Troubleshooting Guide