Testing Pcb Voltages; Ac Power; Adaptor Voltage; Pcb Input Voltage - KERN HFD Service Manual

Zero Balance
 Connect the load cell to a stable DC source of between 5 to 10V
 Connect multimeter to mV and connect to the load cell signal wires
 The meter should read 0.00mV ± approximately 1 % of full load.
If the output reads greater than ±10% of full scale capacity, then the load cell will
require replacement.

10.5 Testing PCB Voltages

If the problem is in the PCB, use a multimeter to check the following voltages

10.6 AC Power

Check the AC power socket out put voltage.
 Voltage must be a -20% and +10% of the normal AC voltage.

Adaptor Voltage

10.7
Check the adaptor output cable connecter voltage
 Voltage must be minimum 9VDC and maximum 15VDC

10.8 PCB Input Voltage

Check the PCB input power connecter voltage
 Voltage must be minimum 9VDC in to the pin AD+

10.9 Check Battery Voltage and Charging Voltage

1. Check the Battery Voltage,
 Voltage must be minimum 6VDC. If below the 6VDC connect the adaptor for
charging
 The battery voltage below the 5.5VDC, replace the battery and install new
7.4V/5.2Ah battery.
2. Check the Battery Charging Voltage;
 Remove the battery connection terminals (Red and Black) from the battery.
 Connect the power and turn on the scale
 Voltage into the terminal minimum 6.5VDC
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