These boards have been removed from mostly new MONITORS with broken screens and should work if properly installed. ACER PREDATOR-Z321QU MONITOR CONTROL BOARD 715G9248-T0A-000-004K. Please verify that your board part number is the same as 715G9248-T0A-000-004K. The part number is the first number left of the /, or the sole number listed. Most often written in title as (part number / board number)