Thermo Scientific 420 Series, Operating And Maintenance Manual

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4-2 Orbital Shaker Thermo Scientific
Section 4
Service
Table 4-2. General Fault Conditions
Tools needed:
Phillips screwdriver
3/8” drive socket wrench with 7/16” socket
1. Remove all connectors and the line cord from the back of the shaker.
2. Lift the front of the shaker and rest it on its back. Remember that the
weight of the shaker is 185 pounds (83.9kg).
Warning The shaker is not stable when on its back. A second person may
be necessary to support the shaker while in this position.
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3. Remove the bottom cabinet cover (8 Phillips screws).
Symptom What to Check and Where to Look
Display is dark, shaker will not operate
Power at the wall outlet
Fuses on the back of the unit are blown
Power switch not turned on
Display is lit, motor will not operate
Voltage selector switch at wrong position
Drive motor fuses inside cabinet are blown
Acrylic lid is not closed
No time value entered into the system (see
Section 2)
Time countdown has been reached (see Section
2)
Display is on, motor operates, display shows
7.5°C or over temp state
Faulty temperature sensor
Faulty overtemperature sensor
Display is on, motor operates, fan(s) do not
run
Blower motor fuses are blown
Connections or wires to fan relay board inter-
rupted
Display is on, heat is on but fans and motor
do not operate
Voltage selector switch
Display on, unit will not operate (Time reads
zero)
Countdown time reached, reset TIME (see
Section 2)
Forgot the Access Code Call Technical Services Department
Adjust Drive V-belt
Tension