HITACHI HA01234 LAMP POWER UNIT OEM ORIGINAL PART THE BALLAST IS THE PART THAT POWERS UP YOUR TELEVISION'S LAMP WHENEVER YOU START UP YOUR DLP SET. YOU MAY NEED TO REPLACE YOUR LAMP BALLAST IF YOUR DLP TELEVISION SET DOES NOT MAKE THE USUAL CLICK OR POWER SURGE-LIKE SOUND WHEN TURNED ON. THE BALLAST MAY ALSO BE DEFECTIVE IF YOU HEAR CONSTANT Works with the following models: Hitachi 50V500A, Hitachi 50VF820, Hitachi 50VG825 Hitachi 55VF820, Hitachi 55VG825, Hitachi 60V500, Hitachi 60VF820, Hitachi 60VG825