Thermo Scientific TSX Series Installation And Operation Manual page 44

Problem
Display is looking dull.
Power failure to the unit.
Unit tripping the circuit
breaker.
Excessive frost build-up
around 
perimeter of door.
Unit is over cooling.
Ultra Low Temperature Freezers
Cause
Screen brightness is too
low.
Power supply stopped /
Breaker switch off.
Shared power source.
Unit plugged into wrong
power outlet.
Unit not grounded.
Use of GFCI for TSX units.
Use of extended cords.
Icing/Frost due to high
relative humidity.
Excessive and prolonged
door openings.
Gasket damage.
Set points may have
changed.
Temperature offset may
have changed.
Unknown.
Solution
From the settings screen, pressing the display button will
show the display.
Adjust the brightness level of the display (Refer Display).
Confirm that the cord is securely plugged in.
Plug another appliance into the outlet to see if power is
present.
Reset circuit breaker to on position and push power button
on user interface and hold for at least 1 second.
Always use a dedicated, properly grounded circuit.
For the TSX series, the ULT should not be connected to a
GFCI (Ground Fault Circuit Interrupter) protected outlet as it
may be subject to nuisance tripping.
Never connect unit to overloaded power source. Always use
a dedicated (separate) circuit.
Plug the unit into proper power source to deliver correct
voltage.
Your unit must be properly grounded in conformity with
national and local electrical codes. Troubleshooting
procedures involving live voltage is dangerous and if done
improperly can result in injury and/or death. 
This troubleshooting should be performed by trained
personnel only.
For the TSX series, the ULT should not be connected to a
GFCI (Ground Fault Circuit Interrupter) protected outlet as it
may be subject to nuisance tripping.
Do not use an extension cord. Ensure the unit supplied power
cord is plugged directly into power outlet.
Check if the location meets requirements. Maximum relative
humidity 60% for temperatures within 15°C to 32°C 
(59°F to 90°F).
Occasionally scrape the ice on the outer door.
Avoid opening door for a prolonged time.
Check for punctures or tears on gasket. Replace if necessary.
Refer Gasket Maintenance.
Adjust the set point to run at desired set point under settings.
Refer Controls.
Try adjusting the offset. Temperature offset can be set in the
Controls screen under settings. (Refer Controls).
Try restarting the unit. If this doesn't help call service.
Troubleshooting Guide | 39