Detecting Electrical Faults - Hach 9186 Instrument Manual

Troubleshooting

9.2 Detecting Electrical Faults

Problem Symptom
No display
No power
Loose connections
Faulty fuse
The power source has the wrong voltage
The cable connecting the power board to the
CPU board is poorly connected
Incorrect connection between the CPU board
and measurement module
Short-circuit in the power board
Faulty hardware. Failed display
The display shows undefined characters
Poor CPU board or processor operation
CPU board hardware
Faulty display
The keyboard doesn't work; the keys are inactive
Poor CPU board operation, external
interference
Bad key pad or display
Incorrect measurement
The instrument has not been correctly
programmed
Faulty CPU board
Display appears to be locked and cannot be altered
Faulty CPU board
Alarm relays do not trigger
The transmitter has not been correctly
programmed
Faulty wiring
Faulty hardware
Output current remains at 0 or 20 mA
Incorrect programming
Poor or faulty connection with peripheral
devices
Faulty output board
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Solution
Check the power supply and the connection.
Check the fuse.
Check the voltage level.
Check that the terminal strips are connected.
Check connections.
Visually inspect the power board.
Call technical support.
Program the instrument to load the default values.
Re-initialize by turning the instrument off for 5 to 10 seconds. Call
technical support.
Call technical support. Order 09125=A=1000
1. Re-initialize by turning the instrument off for 5 to 10 seconds.
2. Check the keys once more.
3. If there is no change, call technical support.
Check the program parameters. Do they match the probe
properties?
Call technical support. Order 09125=A=1000
Check probe connection.
Reinitialize.
Reprogram the instrument.
Turn off the power for 5-10 seconds.
If problems persist, call technical support.
Check that the relay parameters have been programmed.
Make sure that the alarm values are set correctly.
Remove power. Check relay operation with an ohmmeter.
If problems persist, call technical support.
Check the output current parameters.
Check the cables.
Call technical support.