The service documentation identifies several common operational errors and hardware faults:
: If the display blinks >340 , the value exceeds the measurement range. You should repeat the measurement or check the device's calibration. jm105 service manual full
: A standard procedure to verify device readiness. Remove the unit from its docking station and power it on. Select CHECKER from the menu. jm105 service manual full
Without the full manual, replacing a simple $2 rubber pickup roller becomes a guessing game that often breaks plastic clips. jm105 service manual full
Open the checker lid on the charging unit and press the probe tip flat against it until it clicks.
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