
61
SYMPTOMS
PROBLEM
SOLUTION
Reading fluctuates up
and down (noise).
DO probe not properly
connected.
Connect the probe.
Display shows DO
reading blinking.
Reading out of range.
Recalibrate the meter;
Check the sample is
within measurable
range.
Meter fails to calibrate
or gives faulty
readings.
Broken DO probe.
Replace the probe.
At startup the meter
displays Hanna logo
permanently.
One of the keys is
blocked.
Check the keyboard
or contact your local
office.
“Err xx”
message
displayed at startup.
Internal error.
Contact your local
office or any Hanna
Service Center.
Meter shuts off.
Dead accumulators,
Auto Power Off feature
is enabled: in this
case, meter shuts off
after selected period of
non use.
Recharge accumu‑
lators or replace
accumulator; Press
ON/OFF
.
The instrument does
not start when
pressing
ON/OFF
.
Initialization error.
Press and hold down
ON/OFF
for about 20
seconds or disconnect
and then connect one
accumulator.
TROUBLESHOO
TING GUIDE
www.tools.in.th
www.neonics.co.th