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Discussion Starter · #1 ·
I have a Toshiba 50HX81 that has an intermittent problem with movement within a scene. If you are watching what is basically a still camera shot and someone moves within the frame, the brightness and contrast jump around all over the place in the entire picture. This set is under warranty. The problem seems to show up more with HD programming; somewhat less on DVD's and SD programming, so the repair people seem very skeptical since they haven't seen the problem in all its glory. So far they've taken a stab at it and replaced a board which caused more harm than good. They threw off the geometry, and now there seems to be a color shift--all because they replaced a board. After 4 tries at fixing it, it's still doing it. I'm beginning to think I have to live with it. Anyone have any suggestions? I'm planning on writing Toshiba's tech support tomorrow for what it's worth.


Paul
 

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Paul210: I noticed similar behavior on my Tosh 57HLX82 (LCoS) where the brightness would adjust up and down on various shots (rather consistently, I noted) and on certain material exhibited an irritating flicker. I later turned OFF the DNR in all inputs and the problem has gone away. I don't know if this will work in your case, however, but it is very nice to have the problem gone.
 

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Discussion Starter · #3 ·
BTDT


Thanks for the tip. I thought I tried it with DNR on and off, but I'm not really sure now. I'll give anything a try at this point.


Paul
 

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Paul,


I would have also sworn I had already tried this, but for some reason I did not, or not for long enough. One day I just set it to "off" and then noticed that all of the flicker/adjustments had gone away. It has consistently stayed away since then, which makes me really really sure this was the problem on my set.


I don't really need DNR on my sources anyway.
 

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Discussion Starter · #5 ·
The saga continues. The problem is still here. Toshiba referred me to a different repair facility. They sent out some guy that didn't have a clue what an ota set top box is. He couldn't understand how I was receiving anything HD if I didn't have cable. Not to mention that because the problem wasn't an 'all or nothing' kind of thing, he seems to think it's minor. I showed him numerous scenes on a DVD where the problem is VERY evident, but he seems to think that they'll never be able to do anything since it doesn't do it except in certain scenes. They sent their report to Toshiba. Why do I feel like I'm gonna get hosed here?
 

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Paul,


I actually saw this problem again a couple of days ago. It kept up for about an hour and was very irritating (no one else seemed to notice it, or at least didn't comment).


The last couple of days, however, it was completely gone again. What I am wondering is if I was hitting some "high premium sports period" on DirecTV where they over-compress everything else to compensate?


I have only noticed this once on a DVD, and that was way back when I first got the set.


I don't know if yours will settle out or not. jp2 reported having it initially and then it went away. He did also switch out his bulb just for fun (not because of problem) so this may be a factor.


I hope you are able to resolve this quickly. I think it is one of the perils of the bulb-based projection set....
 

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Discussion Starter · #7 ·
BTDT,


My Toshiba is a CRT-based RPTV. It's actually been doing it for quite a long time. I was reluctant to call for service for a long time because it doesn't show up all the time. I had a feeling I would run into unsympathetic technicians and that's exactly the response I got from two different repair facilities. The more they attempt to fix it, the worse the pq becomes. They've replaced a couple boards now, and the color, brightness and geometry are nowhere close to what they were before. Not only do they not know how to fix the problem, they don't know how to calibrate.


All I can say now is I hope Toshiba has some sympathy and will replace this set as I don't think any of their supposed certified technicians can do anything with it. If it can be fixed, it's definitely going to need the TLC of an ISF technician to get it anywhere close to correct.
 

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It sounds like Toshiba may be perpetuating an undocumented "feature" that my two year-old 40H80 (and others of its generation) provides and that is DC Restoration (maintaining a consistent black level) seems to be only enabled in the "Movie" Picture Mode. Without it, contrast/brightness will appear to vary with changes in Average Picture Level (APL). When an object of relatively high luminance value (like the person entering the image in your example) comes in to view, the background becomes darker (black level drifts downward) and vice versa.


The cure is NOT to always use the Movie Picture Mode (which uses factory default settings) but to establish your "Preference" settings starting from the "Movie" mode. As soon as you change one of the video settings (e.g., Contrast) while in Movie mode, it will immediately change to "Preference" mode, but that's O.K.. It will have remembered the switch on of DC Restoration from the Movie mode.


Make note of all of your current Preference settings, switch to Movie mode, re-enter you preferred settings, Save and Exit. That should cure your bouncing video levels. Unfortunately, it won't undo the harm done by inept service technicians.
 

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Discussion Starter · #9 ·
John,


You just described exactly what my set's been doing. I had it set to "Preference" mode, but I'm not sure that I started from "Movie" mode. Also, as I recall reading on other posts, when you start from "Movie" mode, it disables SVM.


Thanks for your comments!


Paul
 

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Hmm. Let me know if this works. I believe I have my Preference settings started from Movie mode, but I still see a brightness adjustment every now and then. I think this is definitely a video processing phenomenon of some sort....
 

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Discussion Starter · #11 ·
John,


I made my preference settings starting in Movie mode. It's been 4 days now and I haven't even seen a hint of a fluctuation in brightness. I think you nailed my problem. Too bad nobody else knew to tell me that before they totally whacked out my TV! Thank you very much for your insight!


BTDT, I hope this helps you as well. I appreciate all your comments and suggestions. This forum is invaluable. Obviously, many of the members here know more tricks of the trade than the TV repair shops do (and possibly more than the manufacturers are willing to admit).


Paul
 
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