Distorted image and separated colors... (1 Viewer)

[shaguo]

I have a Toshiba TW56X81 for about 2 years now and it had great pictures until a couple of days ago when I turned on TV. The image is distorted and the red and blue colors seem mis-aligned. I tried the convergence procedure described in the Toshiba owner's manual, and no use (the red and blue lines drift away too much).

This problem happens only if I use the HD output from my RCA DTC-100 receiver. If I use S-Video or composite from the same receiver, the image and color looks fine (though not as clear as HD). It also works fine with my progressive scan DVD player. Initially I thought either VGA/Component cables or the Audio Authority VGA to Component converter is broken, because when I hook the VGA output from my DTC-100 to one of my computer monitor, the picture has no problem at all. So I bought new cables and new RCA converter and still the same problem.

Any suggestion?

Thanks a lot,

Sha

 

[Kevin P]

You may have a problem with the convergence generator board, but since you say that 480i/480p looks fine, I'm thinking that your set just lost the HD convergence settings (a memory loss of sorts).

Have you tried all the aspect modes (Theater Wide, Full, Standard) in 480i/480p, to verify proper convergence in all of them?

A tech with a service manual should be able to reset the geometry and convergence on the HD side, using the set's service menus, unless there is a hardware problem.

KJP

 

[shaguo]

Hi, Kevin,

You are right about the cause. The serviceman told me that the problem is due to memory loss of the HD board, possibly caused by power surge. 480i/480p is fine. The guy re-adjusted the geometry and convergence of HD board using the TV remote (he did not even touch the TV). It took him 2 hours and cost me over $200 for the work, and the HD picture is not as great as before (though acceptable). I asked the serviceman how to get to the service mode and do the adjustment, and he refused.

Is there any instruction on how to do this? Or is it recommended by you to do this myself?

Thanks,

Sha

 

[Kevin P]

It sounds like your tech did the right thing, but wasn't very thorough. You don't need to open the TV to adjust geometry/convergence, it's done from the remote in the set's service mode.
Check out these sites for Toshiba service mode information:
56 Point Convergence Procedure - disregard the Touch Focus button instructions, that won't apply to your set
Keohi (Errol's) HDTV site
Basically, you'd enter the service mode while displaying a HD signal, then adjust the green to get the geometry right (lines straight and spaced equally apart). Then you'd converge the red to green and the blue to green.
Make sure to write down any values before changing them, in case you have to go back.
You may want to contact Michael TLV or Gregg Loewen. Both these people are ISF certified and know much more about Toshiba tweaks than I do (I'm a Mitsubishi geek myself).
KJP

 

[Gregg Loewen]

HI!

Kevin is right on the money. Make sure you have a HD signal (1080i signal , and not 480P) running when you enter the service menu.

When I was learning how to do convergence I used the instructions found at Keohi TV and thought they were very thorough / useful.

There are also instructions on how to turn down the grid intensity for the convergence menus. Make sure you do this before doing extensive convergence work so you dont get burn in. Even after you turn down the intensity, make sure you don't spend more than 20-30 minutes at a time doing convergence work. Take frequent breaks, making sure you hit the 7 key to save your work, and then switch to some full screen material for another 20-30 minutes.

Best of luck and keep us posted.

Gregg

 

[shaguo]

Kevin, great information! I hope I knew this earlier. Thanks again.

To Gregg: when will you or Michael visit Northern Virginia/DC area again? I definitelly want to sign up for your next trip here.

Sha