I need guidance on replacing the diodes on the ballast board for a mercury lamp.
I'm helping a friend fix her Toshiba DLP TV model 62HM84. The bulb was bad (I could see a melted area inside it) and we replaced it, but it still doesn't start up. You can hear a spark noise as it tries to start the arc.
These Toshiba models are notorious for failure of the lamp's ballast board, so I intend to remove it next and take a look. These boards were made by Rubycon, Toshiba PN 23122468 ballast. I cannot find a schematic. The TV's service manual has the other schematics, but not for the ballast board. The best photo I can find is attached.
The 2 large diodes in the rubbery sleeves D2 and D3, and the R3 1kΩ resistor in front of them fail so often that you can even buy a "repair kit" on e-bay containing these. But he wants $30 for <$5 worth of parts. I refuse.
Best I can tell from other folks reporting successful repair, the diodes are Sanken "damper" diodes FMV-G2GS.
I'm just wondering if there's anything I should know about these, what their role is, and anything to look for if I need to source them from another manufacturer.
I'm helping a friend fix her Toshiba DLP TV model 62HM84. The bulb was bad (I could see a melted area inside it) and we replaced it, but it still doesn't start up. You can hear a spark noise as it tries to start the arc.
These Toshiba models are notorious for failure of the lamp's ballast board, so I intend to remove it next and take a look. These boards were made by Rubycon, Toshiba PN 23122468 ballast. I cannot find a schematic. The TV's service manual has the other schematics, but not for the ballast board. The best photo I can find is attached.
The 2 large diodes in the rubbery sleeves D2 and D3, and the R3 1kΩ resistor in front of them fail so often that you can even buy a "repair kit" on e-bay containing these. But he wants $30 for <$5 worth of parts. I refuse.
Best I can tell from other folks reporting successful repair, the diodes are Sanken "damper" diodes FMV-G2GS.
I'm just wondering if there's anything I should know about these, what their role is, and anything to look for if I need to source them from another manufacturer.