Teledyne T802 11.6.10. CPU

Teledyne API T802 Paramagnetic O2 Analyzer Operation Manual Troubleshooting and Service
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11.6.9.3. STATUS OUTPUTS
The procedure below can be used to test the Status outputs:
1. Connect a jumper between the “D“ pin and the “” pin on the status output
connector.
2. Connect a 1000 ohm resistor between the “+” pin and the pin for the status
output that is being tested.
3. Connect a voltmeter between the “” pin and the pin of the output being
tested (see table below).
Under the DIAG SIGNAL I/O menu (See Section11.1.3), scroll through the
inputs and outputs until you get to the output in question. Alternately turn on and
off the output noting the voltage on the voltmeter, it should vary between 0 volts
for ON and 5 volts for OFF.
Table 11-8: Status Outputs Check
PIN (LEFT TO RIGHT) STATUS
1 SYSTEM OK
2 CONC VALID
3 O2 ZERO CAL
4 O2 SPAN CAL
5 ZERO CAL RNG2
6 CO2 ZERO CAL
7 SPARE
8 SPARE
11.6.10. CPU
There are two major types of failures associated with the CPU board: complete
failure and a failure associated with the Disk-On-Module (DOM) on the CPU
board. If either of these failures occurs, contact the factory.
For complete failures, assuming that the power supplies are operating properly
and the wiring is intact, the CPU is faulty if on power-on, the watchdog LED on
the motherboard is not flashing.
In some rare circumstances, this failure may be caused by a bad IC on the
motherboard, specifically U57, the large, 44 pin device on the lower right hand
side of the board. If this is true, removing U57 from its socket will allow the
instrument to start up but the measurements will be invalid.
If the analyzer stops during initialization (the front panel display shows a fault or
warning message), it is likely that the DOM, the firmware or the configuration
and data files have been corrupted.
07275B DCN6418