Troubleshooting guide – Nova-Tech DO 700 User Manual
Page 30
10.
TROUBLESHOOTING GUIDE
PROBLEM CAUSE
SOLUTION
No display
Main power not switched
on. AC Adapter socket not
inserted properly.
Switch on the power supply.
Re-insert AC Adapter.
“Ur” (Under
range)
“Or” (Over
range)
in primary or
secondary
display
DO or Temperature value
is out of range.
Probe is not connected.
Electrode dirty or broken.
Meter not calibrated.
Confirm measurement condition,
ensure temp is within range.
Check electrode connections.
Check electrode-add electrolyte
&/or replace membrane.
Reset meter & recalibrate.
Meter not
responding to
key press
Manual HOLD or Auto
HOLD is active.
Worn keypad.
Press
to deactivate manual
HOLD.
to
disable Auto Hold feature if
enabled.
Contact Technical Service.
Invalid key; Button is not
functional in the current
operation mode.
Press alternate key.
Select valid key depending on
current mode.
Secondary
display
continually
shows
0 and 100,
during %
calibration
The calibration value is too
high to be accepted as a
0% standard, and too low
to be accepted as a 100%
standard (10.1% to
49.9%), compared against
factory default value.
Service probe.
Check calibration solution.
Check sample conditions (temp,
salinity and pressure settings).
Reset meter.
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