Implement blade is intermittently jumping up or attempting to deep dive.

Symptoms: 

Work is progressing normally but occasionally the blade will suddenly rise up, or attempt to aggressively dig.

Possible Cause:

• A bad USB-to-Serial conversion dongle/adapter is causing corrupted height commands to be sent to iGrade. This can be diagnosed by checking the I/O Voltages page on the iGrade display and observing the last received messages. Occasionally you may see values being received to be truncated or otherwise corrupted.
• Base receiver could have an intermittent failure. See Sudden Vertical Shifts.

Solution:

1. Replace your USB-to-Serial cable with the one recommended. - FTDI US232R.
2. Contact T3RRA or your dealer for a recommended make and model.

Ps