Thermo Fisher Scientific CyberScan DO 300 - Manual (Page 47)

Instruction Manual DO 300
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10 TROUBLE SHOOTING GUIDE
Problem Cause Solution
No display when
turned on a) Batteries not in place
b) Batteries not in correct polarity (+
and – position).
c) Weak batteries
a) Check that batteries are in place
and making good contact.
b) Re-insert batteries with correct
polarity.
c) Replace batteries.
Unstable readings a) Insufficient electrolyte in probe.
b) Air bubbles trapped around the
probe.
c) Dirty probe.
d) Probe not deep enough in
sample.
e) External noise pickup or induction
caused by nearby electric motor.
f) Broken probe.
a) Fill probe with electrolyte &
replace membrane. See page x.
b) Tap probe to remove bubbles.
c) Clean the probe and re-
calibrate.
d) Make sure sample entirely
covers the probe sensors.
e) Move or switch off interfering
motor.
f) Replace probe.
Slow response a) Dirty / Oily probe. a) Clean probe. See Section 9
“Probe Care & Maintenance”.
Not responding to
key press a) HOLD mode in operation.
b) Damaged key pad.
c) Internal program error.
a) Cancel HOLD mode.
b) Return to dealer.
c) Reset all internal programs by
reinserting batteries.
“OR” or “UR” on
upper display a) Probe is shorted.
b) Probe is in out-of-range (OR) or
under range (UR) condition.
d) Broken probe.
a) Test probe. Make sure probe is
fully connected to meter.
b) Use different solution.
d) Replace probe. See Accessories
section.
Temperature
reading erratic or
lower display reads
“OR” a) Temperature of solution is out of
range. a) Heat or cool solution.