[eflyguy]

Talking about service-level settings, not the general consumer settings in the main menu..

I've done it many times, any time I notice the it's drifting near a corner.

We just switched to Dish HD service, and I had to set my 1080i settings (my 65" Diamond rear projection has different settings for 480/1080, and until now my satellite and DVD have been composite at 480i). As they were pretty far out of whack, I decided to do a factory reset.

BAD ANSWER!

The picture was quite good before I reset to factory defaults, I basically just needed to resize the overall screen as I was losing the edges - which I did without issue - but then needed to adjust the convergence around the edges. I've been thru the course and fine adjustments many times without issue, but its always been close to begin with, so if I went in the wrong direction, it was easy to back up.

The red is so far out of alignment, I don't know where to begin - attached a picture of what's happening, it's basically stretching vertically in a non-linear manner from left to right. It's almost like a keystone effect but non-linear.

The Red VLIN setting will narrow down the right side but as it come close, it starts to really compress the bottom left corner, and puts a pretty hefty slant to the left at the top-left. I keep thinking I'll get it close and then use the fine settings to correct it, but I am getting some pretty goofy lines here which has me wondering if I'm chasing the wrong settings.

Note - there's nothing wrong with the circuitry itself. As stated, I started with a pretty good picture, I just needed to correct the overall scale and then fine tune it. I just signed up and posted wondering if there is a basic how-to on what to adjust for various problems posted somewhere (I did search, and the only hits I kept getting were related to circuity repair, not actual steps and tips).

Any links/pointers would be greatly appreciated!
Thanks,
..a

 

[lcaillo]

If you have not done so, read the first ten posts of the convergence repair thread carefully.

I cannot give step by step tutorials as they are different for each brand and many models within brands but I can give you some general guidelines.

Green should be the referece, so get the geometry on the green correct first.

Center the convergence controls to minimize dc offset on the outputs.

Adjust skew and tilt first, then keystone. These will likely interact.

Adjust bow and pincushion next. These will also interact and may affect keystone somewhat.

Adjust width/height and linearity. These will interact.

Do point or fine corrections last.

When you get to the point on a control where it seems to be having less effect, back off and try a related or adjacent control. Continuing to add correction beyond where a control is effective can cause overheating in the output ICs.

When controls interact, use the "halfway rule." Adjust one control half as far as you need to go to get it where you ultimately want it to be. Then do the same with the other. If you can't get them to move together it becomes obvious which way they need to go and you will not overshoot or "chase your tail" with interactions. It seems like it will take more time, but you end up saving time by not making circular adjustments or overshooting correction. It also assures that you do not overcorrect and cause overheating in many cases.

Remember to SAVE the changes...

 

[eflyguy]

That's great, thanks. I didn't see that in the convergence repair thread (I had read thru it, as I saw you postded it in response to pretty much all requests here!)

These simple steps:
Green should be the referece, so get the geometry on the green correct first.
Center the convergence controls to minimize dc offset on the outputs.
Adjust skew and tilt first, then keystone. These will likely interact.
Adjust bow and pincushion next. These will also interact and may affect keystone somewhat.
Adjust width/height and linearity. These will interact.

.. pretty much point me in the right direction. Thanks!!!
..a

 

[eflyguy]

.. all better now!

Thanks again!
..a

 

[lcaillo]

Congratulations! Tell us what you did. It might help someone else in the future.

 

[eflyguy]

Just about what you described. Factory reset again, then manually pulled green in to center as best I could, focusing on skew/tilt first, etc. Big change from how I had generally been doing it was I fiddled with width/height/linear last (before, I was doing this first) - that made things a lot easier.

Red was a bear, but by getting it "straight" before I worked on scale and postion, it seemed to make the height/width/linear settings more effective. Before, when I adjusted those, it would distort the edges badly. With the grid square before I scaled and moved it, it stayed just about square while I moved it.

Makes sense now, but it was really frustrating before..


Does the fact that red is starting out so far out indicate a future problem with the circuitry? Why does red seem to be the most common to fail first?

I'm not afraid to repair the components - I have an EE degree (as well as CS) and have changed out the caps on the DM board already..

Thanks again!