What causes error 4 on 672X analyzer?
672X and backup battery
When a 672X shows ERR 4, it means Memory Loss, default values are in use. This means the back up battery for RAM needs to be replaced. It is located on the back of the display board, but the part number is not given in the manual. The part number is 3A1066 and item description is BATT, NICAD, 3.6V, 110MAH, PC