CurtPalme.com Home Theater Forum

gholt · Joined: 10 Jan 2007 Posts: 47

I'd appreciate some help troubleshooting a problem I've never seen before in one of my Barcos. It's a BD808, and after an image has been on the tube for a few seconds, the red starts to get brighter.

For example, if I project an image of the sun that is yellow, after a few seconds, I see the middle of the image starting to turn orange, and it gets worse for the next 20 seconds or so, and then stays at that level. On a gray projection, it has a very noticeable pink color after a few seconds.

So, what should I be checking? I couldn't find anything in Curt's tutorials or here in the forums.

Thanks in advance for any help you can provide.

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Could be a bad Sanyo video amp on Red...Try swapping video amps.

gholt · Joined: 10 Jan 2007 Posts: 47

Thanks Tom.W. I'm not familiar with that term -- even though I've been using CRTs for several years, I still consider myself a bit of a noob.

Are you referring to the Video output board/CRT socket shown here?
http://www.curtpalme.com/Barco808_Layout10.shtm

Decibel · Joined: 31 May 2007 Posts: 904 Location: Roma - Italia

gholt · Joined: 10 Jan 2007 Posts: 47

Thanks, Decibel.
I have some time in my schedule tomorrow when I can give it a try.

gholt · Joined: 10 Jan 2007 Posts: 47

**Curt Palme** · Posted: Thu Dec 02, 2010 5:24 pm Post subject:

Try resetting the G2 levels in the service menu (so the green LEDs go out on the CRT video cards. The G2 board itself could be bad, I can always send another one.

gholt · Joined: 10 Jan 2007 Posts: 47

**Curt Palme** · Posted: Thu Dec 02, 2010 5:47 pm Post subject:

Go into the service menu to the 'adjust G2 controls' or whatever the menu says (it's been a while!). You then turn the G2 controls on the G2 board so that the green LEDs on the video boards go out. THere's a really small window while rotating those pots where the LEDs go out, so turn the pots slowly, and stop once they blink out. I usually start with the G2 levels low (CCW), then increase the level slowly.

gholt · Joined: 10 Jan 2007 Posts: 47

**Curt Palme** · Posted: Thu Dec 02, 2010 5:56 pm Post subject:

No, the green LEDs are on the video boards as posted by decibel above. They are right above each CRT socket.

Cheers!

gholt · Joined: 10 Jan 2007 Posts: 47

**Curt Palme** · Posted: Thu Dec 02, 2010 6:32 pm Post subject:

OK, let's try this:

THe yellow video cables that go from the motherboard to the video output amplifier over each CRT should be long enough so that you can interchange the red and green ones. That means that the green video signal is now feeding the red, and vice versa. If you reverse the R and G cables going into the RGB input at the back of the set, you'll now send the red video signal through the green video chain, and vice versa.

See if that switching now gets the green tube to change in brightness, or if it stays with the red.

gholt · Joined: 10 Jan 2007 Posts: 47

**Curt Palme** · Posted: Thu Dec 02, 2010 6:47 pm Post subject:

No, just switch the long cable going to the motherboard from the CRT socket. The CRT socket stays in place, as does the video amp, you're just switching the signal coming from the motherboard between tubes.

gholt · Joined: 10 Jan 2007 Posts: 47

**Curt Palme** · Posted: Thu Dec 02, 2010 7:10 pm Post subject:

That should do it! Let me know what you find out.

gholt · Joined: 10 Jan 2007 Posts: 47

The cables from the motherboard to the front of the video cards are not long enough to swap -- even when I tried passing them under the tube.

But I went ahead and swapped the red and green input cables on the back of the projector anyway. So the colors in the desktop are weird, but since we're talking about a yellow sun image (made from red and green light), the sun is still yellow, and the center still turned red.

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Sounds like you could have a short in the CRT gun...See page 2

zGman · Joined: 22 May 2006 Posts: 599

Would swap G2 board before worrying about tube...
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