These boards have been removed from mostly new MONITORS with broken screens and should work if properly installed. VIEWSONIC TD2421 MONITOR CONTROL BOARD 7ZB.A1Q03.0002 / 48.7U004..01M. Please verify that your board part number is the same as 7ZB.A1Q03.0002 / 48.7U004..01M. 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)