This is a mother board fault. Check your +5 VDC logic supply. You may find this low. Clean the mother board edge connection and reseat it into the backplane.
Also look if the logic power supply cable plugs into the backplane or if it uses the screws and terminals. There was a recall/upgrade to a harness that eliminated the plugs. Too much resistance. If you need to adjust the power supply. It has to come off the Control In a Box front cover as the adjusting Potentiometer is hidden. Be careful. Electricity can bite.
Also EMI told me that these power supplies were not self regulating even though they had the potential. He was working on a add on voltage regualtion kit.
George
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)