These boards have been removed from mostly new MONITORS with broken screens and should work if properly installed. ACER XB271HU MONITOR POWER SUPPLY BOARD 4H.30J02.A01. Please verify that your board part number is the same as 4H.30J02.A01. 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)