CurtPalme.com Home Theater Forum

[deewaan1]

Hey all. Thanks for all the help so far. Still got a problem with my tubes though. I have what appears to be two separate sets of scan lines overlapping each other but offset by about a half inch to the left if looking into the tube face. Only one can be controlled by the remote in setup. I have more detail in my original post plus a picture of the tube.

This is the link to the original post

https://www.curtpalme.com/forum_archived/viewtopic.php@t=17866.html

Here's what I've done lately:

I've completely taken the projector apart an cleaned all connections ( connectors, chips and sockets, cable terminations ) from every board including the neck boards. I've tried swapping the HDM, Focus board, VIM, Color Correction, Conv board, Verticle board, Astig board, Video/S-video input board, Moome card, CLM board, HVPS, LVPS. I have also swapped the neck boards between the three tubes. I even tried swapping the ribbon cables to the back panel boards. All this and nothing still has the same issue. No improvement. Tomorrow I am going to get another high voltage splitter and try that. I am also thinking of trying to disable one tube at a time and see if one tube is possibly sending some feedback into the system which is causing the second set of scan lines. What is the best and safest way to disable a tube and still be able to power up the projector to see if the other tubes are still affected?

[Nashou66]

Ok I just saw you swapped out the S-Viedo board. Does it do it with out this board in? I mean did you try running the PJ with out that board.

Also try running it with as many board out of the PJ that aren't needed to turn on, so remove the FCM,Unplug the SAB and CVA Cables and remove the S-video board and the CCM and if you really have to the SWA on the CLM. the PJ will run this way. and maybe, Just maybe you can find out which board or connector on the back plane or MB could cause this.

Too bad you dont have a scope to look on the Vim video signal or on the neck board on one end of the Big orange resistors while having a pattern on. like the greyscale or just a full field pattern. Then we could see where its comming from.

Aslo does it do it with the internal patters too?

Athanasios

[Nashou66]

Oh and try it with one VNB not connected , remove the black Umbilical cord form one VNB at a time.

Athanasios

[antorsae]

[Nashou66]

on the VIM its ok from the video signal and most any other points. but not on the VNB's those resistors are the 85 volt rails but the video goes through them.
So if you put up say a greyscale pattern from the internal video you'll see the stair step on the scope. and you can actually set up G2 and drive this way by looking at the distance of each step. hey should all be equal in distance or hight . I never did this but did use the scope on that part to diagnose a Video problem and its one of the things i noticed.

And for his problem here in this thread he would be able to see if something is wrong if there are any weird variations, like a double stair step patter on the scope. If its not there then its something not in the video chain .

Athanasios

[jcmccorm]

Is there an image on that second set of scan lines? Could it be that the retrace isn't being blanked?

Cary

[Nashou66]

[mp20748]

I've been wondering whyTim no longer post to these threads, or don't post as often as you used to... now I think I understand.



Measure your G2 at either of the neck boards with a meter. Compare that reading to what would be standard.


Remove all three tubes, boards, etc until you have the mother board in your hand. Inspect and clean with 90% Isopropal alcohol, Do not use denatured alcohol here. Or go to Lowes and get a can of CRC Contact cleaner.

Use a small brush (tooth brush) and saturate the entire board brushing more in areas where contacts are.



wrap-around image problems are rarely in the video chain. And the best way to run them down would be to scope the deflection circuit for proper timings. But in this case, the image on the tube is doing what a scope would do with the exception being able to show what the timings are.

The problem here, based on what I'm able to see in the image shows as a deflection problem. Since the HDM has been swapped out numerous times. rule it out as well as the other boards that were already swapped............

[mp20748]

[Nashou66]

It has been mentioned in the other thread to measure the G2 values and compare to standard. Also it has been mentioned it could be a mother board problem or Back plane. He said he tore down the entire PJ and cleaned the contacts for all boards, however it did not go into to detail if he in fact cleaned the mother board and back plane. I say its one of the mother boards also.

So what do you mean you understand why Tim doesn't post much?

Nashou

[Nashou66]

This is his best description of the problem from the other thread.

[mp20748]

[mp20748]

He needs to post a better image. It's hard to tell what's really going on with the double image claim.

[macgyver655]

Is this only on the blue?
If you pull up a grid do you have 2 grids?
If you mute the pic does the other remain.
What does an actual image look like?
Some pics of test pattern and image?
If you run blanking as far as it goes, does it blank both images or just one?

[Nashou66]

I agree, an external grid pattern pic would be more helpful and or a small video of him adjusting the image size to see what happens to the secondary image.

Athanasios

[macgyver655]

[deewaan1]

[deewaan1]

[Nashou66]

Check the HV lead on the blue tube, any leaks possibly?

Athanasios

[deewaan1]