CurtPalme.com Home Theater Forum

Das444 · Joined: 22 Dec 2006 Posts: 125

This is what I have.
Red tube is very dim when playing video. Adjustment menu is bright. internal test pattern crosshair ect are dim. Any one know what could cause this?I did swap neck boards but no change.
NEC XG 1350
Dan

**Curt Palme** · Posted: Sun Feb 05, 2012 7:44 pm Post subject:

OK, as you already changed, my first guess would have been the video neck board. Since you've changed that, the next guess would be almost any board in the card cage. The AKB (auto brightness) control is set by the system board, but can also be affected by any other board in the set.

I had one of the video processing boards smoke a transistor once in a set, causing very dim blue (I think), on signal and menus. About all you can do is swap them. Also try going into the color balance menu and see if it brightens up. that would possibly indicate a system board glitch. Doing a new signal entry might solve it as well. Also try turning the AKB setting on and off.

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 1949 Location: QLD, Australia

What happens when you press the KELVIN button? Ive got a very simular issue with my PG.

**AnalogRocks** · Posted: Mon Feb 06, 2012 5:00 am Post subject:

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 1949 Location: QLD, Australia

Then what happens? Laughing

**AnalogRocks** · Posted: Mon Feb 06, 2012 6:05 am Post subject:

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 1949 Location: QLD, Australia

HAHAHAHA!! Youre a clown Wink

Might be able to cancel my red dim issue too by the looks, im in the test phase, but thus far, success seems to have come in the way of replacing almost all the caps on the video output board...

Das444 · Joined: 22 Dec 2006 Posts: 125

Case,
Blue and green are working fine I'm going pull some boards today and have a look. (If I only knew what to look for).
Dan

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 1949 Location: QLD, Australia

Yeah Dan, my issue will quite likely be different to yours, however when i was to press KELVIN on my remote, my RED would then brighten up to be spot on where it should be, then in a while, it would be too bright.

If i left AKB turned on, it would be perfectly fine, so i was wondering if yours follows this trend or if it remains constantly dim.

I just replaced almost every capacitor on the video output board ( most of them were leaking, which they were not 9 months ago ), and that seems to have solved the issue, it is now abit brighter and has better colour than it has had for a long time.

Das444 · Joined: 22 Dec 2006 Posts: 125

Case,
I have come across something else going on here. The blanking is red on all sides not black as it should be. Could it be a focus yoke coil?

Tom.W · Joined: 09 Mar 2006 Posts: 6368

With no input signal are all the tubes turned fully off ?

**Curt Palme** · Posted: Tue Feb 07, 2012 3:01 pm Post subject:

No, what you have is that the black level is too high on the tube, illuminating the whole raster, along with weak video. You're seeing the whole raster lit up on hte screen, blanking won't get rid of that. I still say it's one of the video boards or a problem in the system board.

What does happen when you go into the 'kelvin' setting?

Das444 · Joined: 22 Dec 2006 Posts: 125

Curt,
What is the switch for on the side of the front yoke at the tube bell? maybe it was bumped.(when adjusting)

What does happen when you go into the 'kelvin' setting?

I'm at work, I will check when I get home.
Dan

Jeremy112 · Joined: 28 Sep 2006 Posts: 1441 Location: Fond du Lac, WI

I wonder if our 2 problems are related Das,

You say you see red when you use blanking, I see blue when I use blanking, and the blue raster is slightly visible on my screen, and fully visible on the tube face, the red and green do not do this...

I do not use blanking for this very reason. Curt would the "Black Level" you are speaking of be the Black Bias setting? or would it be the black level of the kelvin setting?

I have done the G2 adjustments and my G2 Voltages are right where they should be, but I know that I shouldn't be seeing blue raster on screen...

Will be interesting to see where this thread leads

**Curt Palme** · Posted: Tue Feb 07, 2012 6:00 pm Post subject:

A switch on the yoke? That's asking for trouble. Can you post a pix? That won't have anything to do with the red though.

Jeremy, the black level is in a 'super secret' hidden menu, it's locked out in the reference menu. I won't give the password out for that, sorry.

THe user adjustable black and white levels in the kelvin menu allow for tweaking as the tubes wear, but if the set is grossly out of whack for whatever reason, it needs a setup by a tech.

Das444 · Joined: 22 Dec 2006 Posts: 125

Tom W
With no input signal are all the tubes turned fully off ? Yes
Curt
What I thought was switch is some adjustment. But would not move by just bumping it.

What does happen when you go into the 'kelvin' setting?[quote]
No change

**Curt Palme** · Posted: Tue Feb 07, 2012 10:58 pm Post subject:

Whatever that switch is, don't touch it! Disconnecting any yoke winding will instantly spot burn the tube if the set is on.

Das444 · Joined: 22 Dec 2006 Posts: 125

Curt
That is a pic of a spare yoke. I adjusted the red off center to show you the menu screen. When I go to any test pattern the blue and green are bright red is dim. I'm tring to give you as much info as I can so can send me what you think I may need to fix this. I will pm you with the board numbers.

Jeremy112 · Joined: 28 Sep 2006 Posts: 1441 Location: Fond du Lac, WI

**Curt Palme** · Posted: Wed Feb 08, 2012 3:32 am Post subject:

Jeremy, send DAS444 a bit of your red, and both of you are set.

Sorry, not posting that password.

BTW, DAS or Jeremy, did you guys change tubes at all, and leave the red original, but changed the G and B? Different emissions could cause this problem (mixing high and low hour tubes).