make sure that the machine moves free in the X axis. Make sure the rails have the proper amount of grease and the seals are not binding. The heat stop is more sensitive in slow movement (IE G80 pickups and home outs) because the machine is looking for an over current % to detect any obstruction. Since you use less amperage when moving slow the machine trips out easier. If you see no issues with any of the things mentioned above try to move the wires from the X drive to the Y drive and see if the alarm goes to the Y axis or if the alarm stays in the X. If the alarm goes to the Y axis your drive may be going bad.