CurtPalme.com Home Theater Forum

[ben12345]

I've just got my Data 800 set up the way I want (showing Sky HD at 1080i) and now i've got a problem:

My blacks keep going blue or red, so I have to keep turning down the G2 adjustment for the relevant tube, and then turning up the gain. Each time I adjust it, it might last 5-10 hours, before my blacks aren't black anymore.

Problem is now, that when there is a bright area on the screen, such as a menu bar or credits, then this bright area creates a horizontal bar across the screen of that colour. It only seems to happen for the blue and red, so i'm guessing this has to do with the lower grid voltage, as a result of turning down the G2 controls.

Is this an indication of a bad focus block, or is there more to it?

Thanks,
Ben

[Curt Palme]

It could be, but I'd suspect your video output boards. I've got all parts in stock for cheap for the 800.

[Curt Palme]

It could be, but I'd suspect your video output boards. I've got all parts in stock for cheap for the 800.

[ben12345]

Thanks Curt,

Is that what they refer to in the service manual as the 'RGB Output module'? or the 'Quad decoder and RGB amplifier'?

Seems strange that it started happening on two tubes at the same time. Although I did notice that the blue needs more frequent tweaking than the red.

Cheers,
Ben

[Tom.W]

Read this section on the RGB amp failure and the 2SK511

http://www.lynxxx.nl/barco/fet.asp

Also read this thread...

http://www.curtpalme.com/forum/viewtopic.php?p=175324#175324

[ben12345]

Tom,

That looks exactly like my problem! I'd better get those FETs on order asap and avoid using the set in the meantime.

Thanks for your help,

Ben.

[Tom.W]

The bastard FET from hell !