currently we have a machine that was running for about 2 years with no problem, now we are having a problem, we are not getting a feedback fault we are getting a position error, this happens with 3 probes that are all the same, installed in the same spot, The probe works for a while and then it sends a odd position back that does not exist the number is 412 but its is only a 67 inch probe, we get the same thing no matter which probe is in, we have put new cables in and have looked at the noise, It seems to run for a while then it faults and acts like it lost position, when the probe is removed we have tested it with a magnet running it up and down and get good solid number no matter where we put the magnet. It seems to fault when only installed in the machine, we have also looked for mechanical problems but have not found anything, any idea will be helpful.