OHAUS NV212 - Page 23

CHAPTER 2 DIAGNOSTIC GUIDE
Navigator Series Service Manual 17 Ohaus Corporation www.ohaus.com
TABLE 2-1. DIAGNOSTIC GUIDE
Symptom
Possible Cause
Remedy
Cannot turn on
No power to scale
Check battery and / or AC Adapter
connections.
Verify 12VAC at the Power Jack wire
connection to the PCB. If using batteries
check battery voltage at the PCB battery
connections.
Defective PCB
Replace PCB
Incorrect weight
reading
Internal mechanical interference
Verify the pan Support is not contacting
the top housing
Check that the shipping lock is not
touching the Pan Support.
Verify that the down-stops are not hitting
during normal operation.
Improper calibration
Calibration performed with the
Shipping Lock “On”
Perform span calibration
Poor linearity performance
Perform linearity calibration
Unstable environment- vibration,
air currents or changing
temperature
Move scale to suitable location, allow
scale to stabilize its temperature
Bad load cell
Replace load cell
Poor
repeatability
Internal mechanical interference
Verify the pan Support is not contacting
the top housing
Check that the shipping lock is not
touching the Pan Support.
Bad load cell
Replace load cell
Cannot calibrate
Unstable environment- vibration,
air currents or changing
temperature
Move scale to suitable location, allow
scale to stabilize its temperature
Incorrect calibration weight
Use correct calibration weight
Poor accuracy
See above – Incorrect weight reading
Cannot access
mode or unit
Mode or unit not enabled
Enter menu and enable mode or unit
RS232, USB or
Ethernet
interface not
working
Scale menu settings not proper
Connected computer settings are
not correct.
See Interface User Manual for proper
settings
Poor Cable connection
Check cable connection