CurtPalme.com Home Theater Forum

RVonse · Joined: 09 Mar 2006 Posts: 3152

I recently had a failure of the H card in my Barco 1208 and when I installed another H card it came up again but then I noticed distortion but only on the very left side. It is as though the screen is textured like a curtain sort of like a ringing pattern. I thought at first that maybe the spare H card I had was bad but today I was able to fix the old one and now both H cards are looking exactly the same.

I figure I either I bumped something and created another problem when I was switching cards or there must be something yet wrong with my projector. Perhaps whatever part is still bad caused the first H card to fail?

This really has me stumped. The only thing that comes to my mind would be the quad or the splitter. I reseated the cables but no change.

Has anyone ever seen a left side distortion like this?

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

That is ringing. the video signal doesn't have enough time to settle down coming out of the blanked section of video. increase the porch settings helps. since its a different H card that could be it as I found different HDM's some times need a slightly different timing setting.

But it could also be that H card needs some service, like in a few new caps etc.

Athanasios

RVonse · Joined: 09 Mar 2006 Posts: 3152

I appreciate your thoughts on this. Until you posted I had not even thought about it being a video issue. But as I think about it now the video can't be good either or you would see a consistant even color.

It does look very much like ringing but here's the thing. When I put up the convergence grid pattern the lines are slightly bent on that side. All 3 colors are distorted and bend equally on each ring so that the grid manages to still stay in perfect convergence. I think that is why I was going off in the deflection or HV direction.

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

Take a close look at your deflection coils. Its a long shot but check for any signs of damage.

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

i wont use the pj anymore until you found your problem or it might take out the h board again.
i dont think all 3 deflection coils went bad all of a sudden.
bad video module maybe?

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

RVonse · Joined: 09 Mar 2006 Posts: 3152

RVonse · Joined: 09 Mar 2006 Posts: 3152

Good grief, I would never have guessed how hard it is to swap out the deflection switching board. It wouldn't be so bad if the small wires to it had connectors that could be removed. But as it is, looks like you have to dig deep into the motherboard (which ain't easy either) in order to unhook control cables. I kind of hate to go to that extreme at this point because I will have to remove the neck board and run the risk of adding further problems and also getting the green tube out of adjustment. I wish there was another way but at this point it don't look promising.

If I knew for sure all this trouble would be worth it I would go forward but right now I might just put up with the distortion. When you watch a movie you really don't see it at all.

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

Just check for any signs of overheating on the existing coils. This whole thing reminds me of the problem Bjorn had with his 1209...

http://home.c2i.net/tomcat/1209.htm

RVonse · Joined: 09 Mar 2006 Posts: 3152

That looks just exactly what my problem is. Thank you for sharing Tom.

RVonse · Joined: 09 Mar 2006 Posts: 3152

All the coils on the deflection board are running pretty cool. The coil on the H card is a little warm but that coil looks like new and a whole lot better than what Bjorn had. Furthermore, its not clear to me if the heat came from the coil or the mosfet heat sink. And I get exactly the same symptoms with both of my H cards leading me away from that particular coil.

What is really interesting is that when I bump up the resolution the ringing starts to become much less objectionable. The picture above is at 960p but at 1080p it almost goes away. I could and probably should just leave the resolution at 1080p except that one of my htpc's can't do that high.

As a last resort I will purchase another video card for my upper htpc and just leave things at 1080p though. I'm also going to start a similar thread to this over at AVS and see if I can get any comments out of Bjorn or those other experts.

RVonse · Joined: 09 Mar 2006 Posts: 3152

With help from another forum member I was able to fix the problem! It turned out to be 3 resistors (R13, R23, and R33) on the deflection switching board. Had I swapped out the delection board as Tom W had suggested, that would have fixed the problem as well.

These 3 resistors do the same thing for the sweep of each color and there is a special fusable lead that had melted on each resistor. Once I found the open lead it was just a matter of soldering the leads together again. Apparently, when I blew up the H card there must have been excessive current through all of these resistors that caused the leads to blow.

My picture is looking perfect again. Thanks for everyones help here!