D-ILA The burn problem - Need info and comments - AVS | Home Theater Discussions And Reviews
Digital Hi-End Projectors - $3,000+ USD MSRP > D-ILA The burn problem - Need info and comments
Julio de la Orden's Avatar Julio de la Orden 12:55 PM 05-04-2001
Hi,

I saw at the FAQ that there is topic regarding the burn problem, like you find with CRT.

I traied to recover the file from the archive and no succes.

Can any body refresh the info related to it.

I have now a G-20 that presents a burn in the panel, or memory effect, that maintains the previus image in the back of the new image, and washed out.

For me this is the first time I saw this, and have no idea what to do about it.

What are the others experience ?

Best regards,

Julio

BTW, I´m using a Vigatec scaler, and all type of sources, if that helps.

David Panko's Avatar David Panko 01:38 PM 05-04-2001
Hi Julio,

Here's the thread:
DILA and Image Latency

Cheers,
Dave.
mfrizzz's Avatar mfrizzz 10:48 PM 05-05-2001
Hi, I've been dealing with this problem with my G-11. Here is what I know: I bought the projector in December, and noticed about six weeks ago that scores from basketball games and tool bars from pc games would reappear. I sent the projector to JVC for a repair. When it came back, it seemed better and I shipped it off to cliff for calibration. After I played a pc game last weekend, the problem was back again. I talked to alan and cliff about it, and Cliff put me in touch with a very bright techie at JVC who exlained what is going on. Unfortunately, this is normal behavior for the projector. If a fixed image stays on long enough, its memory stays on the LCD panel. But as long as the image eventually goes away, there is nothing wrong with your projector. If you turn the projector off, and unplug it, this may help clear the image quicker. If the image does not go away, your projector probably will need a new panel. Now to complicate things even more, there is something that I believe is called the "Com voltage adjustment.'' If this is out of whack, then you are likely to get this fixed image problem more often than on projectors that are properly adjusted. When I last talked to Cliff, he was in the process of learning how to make this adjustment so that he can perform it on projectors when he is doing calibrations. It is also done by the JVC techies. Apparently, they did adjust mine so that my problem should not appear as often. The really strange thing is that some projectors seem to have this problem, while others don't. Go figure. But the most important thing is that, it is not a serious or fatal condition unless the image doesn't go away...which means I'm about to play Age of Empires on a 10 foot screen and do some serious late night pillaging!!!!
mike
kevin gilmore's Avatar kevin gilmore 10:03 PM 05-06-2001
Yes its the common voltage bias. There is one adjustment for
each of the three panels. There is only one correct way to adjust
this. You need a fast photodetector of some kind with a response
time less than 1 millisecond, and an oscilliscope. You have to
minimise the ac and balance the dc levels.
Large area silicon photodetectors for laser use work great.
So do photomultiplier tubes when driven into low impedance loads.
Colorimeters as such need not apply. Although with the right
firmware it may be possible to make one of these devices function.

By the way, adjusting the projector to produce absolutely the
best blacks, aggrivates this problem severly.

[This message has been edited by kevin gilmore (edited 05-06-2001).]
RonF's Avatar RonF 12:53 AM 05-07-2001
Another JVC "tech" person told me running snow for 5 or so hours can possibly help correct a burn in. Maybe snow from fringe over the air channel? I don't know what else you do for snow.

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Ron
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