Barnstead International MIRAK 725 Series, Operation Manual And Parts List, Page: 27 / 36

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Problem Solution
Unit is not operating at all. Check power.
Replace circuit breaker on power switch.
Unit is stirring or heating, but no lights Check cable to the display board.
are lit on the display.
Only the power light is lit on the display. Check ribbon cable connection from the power board to the
logic board. It may be upside down.
Replace display board.
Some digits of the display are not lit. Replace display board.
Display does not increase or decrease when Check ribbon cable from knob to logic board.
knob turned.
Replace ribbon cable from knob to logic board.
Replace logic board.
Replace encoder switch(es) on knob(s).
Speed or temperature display does not Check ribbon cable from knob to logic board.
change when knob is pushed.
Replace logic board.
Unit does not stir. Check to see if something is interfering with the motor
preventing it from spinning.
Replace power board or logic board.
Replace motor.
Unit does not heat. Check heating element. If resistance across element is
greater than 100
Ω , replace element.
Check connection of wires from element to power board.
Check triac located on bottom cover of unit.
Replace power board or logic board.
Display is reading erratic top plate temperature Replace top plate assembly.
and/or the unit takes a long time to boil liquid
without a probe.
Display is reading erratic solution temperature. Replace probe.
Troubleshooting