Samsung RF22K9381 Troubleshooting Manual page 2

Some time
Make sure before measuring voltage of any
DC component that circuit ground is used.
Any marked GND on the main PCB will be
your circuit ground.
If Chassis ground is used, measurements
will be incorrect.
A Sensor Resistance over 100K ohm is considered OPEN
A Sensor Resistance under 2K ohm is considered Shorted
But Note that a sensor could also give wrong values if it is
out of tolerance