TROUBLESHOOTING & REPAIR PROCEDURES Model 400E Ozone Analyzer
Instruction Manual
258 P/N 04316 Rev: B
11.5.2. DC Power Supply
If you have determined that the analyzer’s AC mains power is working, but the unit
is still not operating properly, there may be a problem with one of the instrument’s
switching power supplies. The supplies can have two faults, namely no DC output,
and noisy output.
To assist tracing DC Power Supply problems, the wiring used to connect the various
printed circuit assemblies and DC Powered components and the associated test
points on the Relay Board follow a standard color-coding scheme as defined in
Table 11-3.
Table 11-3: DC Power Test Point and Wiring Color Codes
Name Test Point# TP and Wire Color
Dgnd 1 Black
+5V 2 Red
Agnd 3 Green
+15V 4 Blue
-15V 5 Yellow
+12V 6 Purple
+12R 7 Orange
A Voltmeter should be used to verify that the DC voltages are correct per the values
in below, and an oscilloscope, in AC mode, with band limiting turned on, can be
used to evaluate if the supplies are producing excessive noise (> 100 mV p-p).
Table 11-4: DC Power Supply Acceptable Levels
CHECK Relay Board Test Points
From Test
Point
To Test Point
Power
Supply
Assy
Voltage
Name # Name #
Min V Max V
PS1 +5 Dgnd 1 +5 2 4.8 5.25
PS1 +15 Agnd 3 +15 4 13.5 16V
PS1 -15 Agnd 3 -15V 5 -14V -16V
PS1 Agnd Agnd 3 Dgnd 1 -0.05 0.05
PS1 Chassis Dgnd 1 Chassis N/A -0.05 0.05
PS2 +12 +12V Ret 6 +12V 7 11.75 12.5
PS2 Dgnd +12V Ret 6 Dgnd 1 -0.05 0.05
To Next Page
Loading...
