I have an Aquapure 1400 system that is in its fifth year of use. I experienced an intermittent General Fault error code (120 mostly, 121 at times). I replaced the cell, tri-sensor and DC power cord but still got the same error codes. A local Jandy service guy then replaced the PCB power interface board but I am still getting the same errors! Chemistry is all good. Any thoughts?? Thanks in advance.