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Discussion Starter · #1 ·
I started a new thread for a problem I have. I t looks like my new 1031 does not scan about 1/15 of the picture. When you look at the screen /projector is still on the floor/ left side of the

picture is black, real CRT black, then it become clearer . The rest of the screen looks perfect. It seems that electrons don't draw picture on the face of the tube. Maybe Jason could help?

P.S.Thanks for any input. Robert
 

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Check the tube faces. I bet the picture is shifted horizontally, and the raster is off the side of the tubes.


- David
 

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Discussion Starter · #3 ·
Thanks. I wish it was so simple. Rasster is in the center of the tube face. When you turn up contrast the picture widens on the left side. I have the projector running now. One more thing. When I looked inside tubes I could see that all left side contures are little distorted. My wife is laughing now. She said she just imagined hundreds of man of different age looking inside their projector's tubes.

This is our third crt in eight years and she likes all of them. Robert
 

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Robert ,

-- Start simple and try the Composite video input from a different source and see if you have the same issue [ this will help track down the problem - if it is the 1031Q or the Source ] .

---- Jason
 

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Yes, the 1031 has blanking. The pots are under the convergence board.

Jason probably knows the EXACT pots.


Marc
 

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Yep ,

-- as Marc stated they are under the main convergence board and are labled as such . Look for a small group of pots near the left side of the board [ looking from behind the PJ ] .

---- Would be great if that solved your problem :) .

----- Jason
 

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Discussion Starter · #8 ·
Thanks again Jason. The blanking does not work for RGB. It just makes picture bigger or smaller. It does not solve my problem. The left side of the picture is not

scanned. It moves with the size of the picture.I am totaly lost.Robert
 

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Well , this looks like one for Kieth or Curt - sorry .

-- I have no idea but it sounds as if it is going to require some form of repair :( .

----- Jason
 

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Three CRTs in 8 years!!?? A collector or just plain bad luck ;-)


Have you centered all the convergence pots (fine and coarse) before you went and fiddled with the blanking etc...?


My two cents.
 

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I adjusted the pots on the board under the convergence board (I think it is called the DA board?) and I was able to recreate the problem you mention. I can turn the pot to correct it again. This pot is toward the back of the board, farthest from the tube faces, with a group of several other pots. I could also recreate this problem by pushing the refresh rate higher than 60hz, which is a bad idea on this projector. If you are using a home theater PC, make sure the resolution and refresh settings are within the limits of the projector.


Good luck!


Matt
 

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Discussion Starter · #12 ·
I tried to do what you advised but no luck. The pots on the board you described are for regulating the size of the picture in RGB mode it is not a blanking. As I stated earlier the problem moves with the screen size. I suspect it has to do something with the timing of the signal. The electrons start to scan the face of the tube too late thus not drawing the left side of the screen. What I noticed too that the brighter the picture the error diminishes.Robert
 

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I think there are two versions of DA board for the 1031 and one does not have all the blanking adjustments.


Anyway on DA board the RV501 and RV504 pots should adjust the horizontal blanking size and position.


If you use htpc and powerstrip you could try adjusting horizontal sync width and front and back porch.
 

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I thought of those things as well guys but robnec tested it with Composite video and had the same issue so I don't think adjusting any timing settings is going to help his situation :( .

---- Jason
 

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I'm going to guess that you have some dry capacitors in the unit. My guess might be the smallish filter caps that filter the G2 voltage going to the tubes. Without a scope to check the various waveforms and lines for AC hash caused by the caps not filtering this out, this coule be a tough troubleshooting.


What I am fairly sure of is that no amount of pot tweaking (for those that know what pots to adjust, 'misadjusting' is the term for those that twist at random!) will solve your issue, sorry!


Curt
 

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Discussion Starter · #16 ·
I believe that tweaking the pots will not help. As I said before I am using CRT projectors for over eight years so even not being the train technician I have some experience. What bothers me tough is a fact that internal signals are displayed correctly. Thanks for the input. Robert
 

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If you mean the testpattern, yes that is strange cause it's fed through the same circuits as the composite signal although the timing could differ.


This could be a calibration problem but just like Curt said it probably requires some measuring with a scope to find...
 
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