Teledyne 6200T - Sulfides Analyzer - Manual (Page 252)

Troubleshooting Model 6200T Total Sulfur Analyzer
252 Teledyne Analytical Instruments
AC Configuration of the pump is accomplished via an in-line, hard wired, set of
connections. Call Teledyne Analytical Instruments’s Customer Service Department for
more information.
12.6.2. DC Power Supply
If you have determined that the analyzer’s AC main 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, which convert AC power to 5 and ±15 V (PS1) as well as +12
V DC power (PS2). The supplies can either have DC output at all or a noisy output
(fluctuating).
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 12-4.
Table 12-4: DC Power Test Point and Wiring Color Code
NAME TEST POINT# COLOR DEFINITION
DGND 1 Black Digital ground
+5V 2 Red
AGND 3 Green Analog ground
+15V 4 Blue
-15V 5 Yellow
+12V 6 Purple
+12R 7 Orange 12 V return (ground) line
A voltmeter should be used to verify that the DC voltages are correct as listed in Table
12-4. An oscilloscope, in AC mode and with band limiting turned on, can be used to
evaluate if the supplies are excessively noisy (>100 mV peak-to-peak).
Table 12-5: DC Power Supply Acceptable Levels
POWER
SUPPLY
VOLTAGE
CHECK RELAY BOARD TEST POINTS
MIN V MAX V FROM TEST POINT TO TEST POINT
NAME # NAME #
PS1 +5 DGND 1 +5 2 +4.80 +5.25
PS1 +15 AGND 3 +15 4 +13.5 +16.0
PS1 -15 AGND 3 -15V 5 -14.0 -16.0
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 +11.8 +12.5
PS2 DGND +12V Ret 6 DGND 1 -0.05 +0.05
12.6.3. I
2
C Bus
Operation of the I 2 C bus can be verified by observing the behavior of D1 on the relay
PCA & D2 on the Valve Driver PCA . Assuming that the DC power supplies are
operating properly, the I
2 C bus is operating properly if: D1 on the relay PCA and D2 of
the Valve Driver PCA are flashing
There is a problem with the I
2 C bus if both D1 on the relay PCA and D2 of the Valve
Driver PCA are ON/OFF constantly.