[Target317]

I recently mounted my 1030Q in a new location and redid the convergence. Yesterday I decided I could make it slightly better, so I took the cover off. I had the projector turned on and as soon as the cover came off, the image changed. It is now warped severely, almost like a CRT monitor when it needs to be degaussed. There are several interference lines running horizontally through the image. This happened before I had touched any of the convergence controls. I think something must have shorted when the cover came off, or a wire may have been pulled loose. I have checked everything I can see, and as far as I can tell there are no shorts or disconnected wires though. The image is bowed in a way such that no convergence controls can make it better. In fact, when I change the convergence pots, the image flickers and the tube is not modified in the way it should be. For instance, I will turn the pot to make the blue CRT wider, and the green and red CRT images will move and bend. The issue is not the source as it affects the grid image as well. It seems like there is a problem with the signal being send to the tubes and something is grounded or shorted somewhere. This projector has been through a lot physically as far as shipping and moving goes, so I don't think me touching it lightly to remove the cover caused this problem. Has anyone seen a similar problem or have an idea as to what boards/wires I can check that could have been messed up when I removed the cover?

 

[Maxxarcade]

Did the cover hit the G2 adjustment knobs when you pulled it off? Also you might want to look at the transistors that are mounted to the frame on the sides of the projector and make sure the pins didn't get bent over and touch the frame. But I'm sure that would have made the projector shut down anyway.


There's not much that the cover can hit to make that happen, unless maybe a connector is loose somewhere that fell off when you moved it around to take the cover off.


Also a screenshot would help, and if you can't figure it out, I can probably look at my 1030q and see what might cause that.

 

[Curt Palme]

Flip up the main PC boards, and between the B and G tubes is a vertical board that sometimes comes loose. Make sure it's sitting in it's tracks, that should do it.


Curt

 

[Target317]

Here are a few screen shots. The grid image shows how the image is bowed. The image of a movie shows the interference lines running horizontally. Hope this helps.

 

[Target317]

Here's the second image.

 

[Maxxarcade]

Curt, do you mean the EA board? I thought that this was just the horizontal deflection and HV power supply. It lookes like the problem is only in the Vertical, since the Horizontal linearity looks fine, but correct me if I'm wrong.


I'd say most likely something on the DA or DB board came loose. Could even be the cute little metal prop stick is laying on the DB board, or the metal frame that holds the boards could be touching it...


Anyway, it's a problem I've never seen. Interesting.

 

[Target317]

Maybe the pictures don't do the problem justice. The vertical lines aren't messed up at all. The horizontal lines are the ones that are warped. The board Curt mentioned was indeed loose. Of the four corner brackets/tracks, two are missing and one is broken. The two bottom ones are in place and I have readjusted it so that the board is not loose like it was before, but this hasn't changed the image at all. If this board is for horizontal deflection, it would make sense that this could be causing the problem, but even when I move the board to be in the position it would with all four brackets, the image does not change. Any other ideas or anything else I should try with that board?

 

[Maxxarcade]

It does get confusing, but the vertical lines are nice and evenly spaced from left to right, which means the horizontal deflection and geometry is working right. It's having problems drawing straight scanlines top to bottom, so that would be a vertical geometry problem. Because the beam is moving up and down when it is not supposed to.

 

[Target317]

That would make sense then. Obviously I don't know a lot about the workings of the projector. Is there a similar board to control vertical deflection? Any other suggestions would be helpful. Thanks.

 

[Maxxarcade]

After I thought about it for a minute, I'm pretty sure the DA board puts out the master signals that control the geometry. Then they go to the DB board (convergence board) and get modified and distributed to each tube's convergence coil according to how the adjustments are set for each tube. Since all three tubes are getting distorted in different ways, I'd say the convergence board isn't doing it's job quite right. It may be missing a signal from the DA board though, too.


I know that all the connectors between the DB and DA have those really small wires that can break off right at the pins, and sometimes they're not obvious.


I'm pretty sure the EA board won't mess up the vertical geometry. I'd check the DB board first, then the DA. I wish I had some time to look at the schematics and give it some thought, but I have to get some sleep for work tomorrow. I'd be glad to help more later on if I can.

 

[Maxxarcade]

And I almost forgot- check all the little fuses on the convergence board, and all the little connectors by them with the yellow and green wires. One of the fuses could be blown, or loose in it's holder.

 

[Target317]

Thanks for the ideas. The fuses are all fine and there is no noticeable damage to the da or db boards. All the little wire connections are pushed in tightly as far as I can tell. Any other suggestions? This item was once dropped in shipping and it didn't hurt the projector, so I'm assuming that the light movement of taking the cover off probably didn't do this damage, but I was very careful and I don't think anything got shorted as the cover came off. It's been a very frustrating problem since nothing really happened to cause it. Thanks again to anyone with ideas.