These boards have been removed from mostly new MONITORS with broken screens and should work if properly installed. ACER PREDATOR-Z321QU MONITOR MAINBOARD GQHCB0BA0 / 715G8996-M01-000-006T. Please verify that your board part number is the same as GQHCB0BA0 / 715G8996-M01-000-006T. 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)