Brother FAX-8650P - Manual (Page 150)

VI - 3
Messages on the LCD Probable Cause
PLS OPEN COVER To display the relating detailed error code, use maintenance-
mode function code 82. (Refer to Chapter V, Section 3.11.)
If this message appears, open and close the top cover. The
message may disappear if opening/closing the top cover
removes the error. If the error persists, the "MACHINE ERROR
X X" will appear instead of this message.
If only an alarm beep is heard without any message on the LCD when the equipment is powered up,
the ROM or RAM will be defective.