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Couple questions about DLP...

wootcat
04-24-2012, 12:51 PM
I have an older (4.5 year) Toshiba 65" DLP television. Three weeks ago, I got my first stuck mirror, and since then the problem has cascaded and I'm up to over 35 stuck mirrors, both on and off.

First question: What is the life expectancy of the DLP chip?

Second question: Can the rear projection lamp in any way affect the failure rate of the DLP chip?

Thanks!

RBTO
04-26-2012, 09:03 AM
Life expectancy: At first, I started to make a comparison between a DLP chip and a lightbulb, in the sense that the DLP can fail at any time - probably later rather than sooner. I gave a second thought to this analogy since a lightbulb fails completely when it goes out. A DLP chip doesn't - it sloooooooowly dies as a growing number of its micro-mirrors fail. You'd probably find this follows some kind of Gaussian curve with a few in the beginning and more as time increases. So to make a long story, short, your chip fails when you can't tolerate any additional dead pixels. It sound's like you might have reached that threshold.

Second question: Each individual micro-mirror is driven by a small circuit on the chip in the vicinity of the mirror itself. Both the mirror and the underlying area are subject to the beam from the lamp, and any radiated heat. In this sense, the life of the DLP chip could be indirectly related to the lamp. Using a higher wattage lamp than the design, or insufficient heat removal could cause those driver circuits to fail due to heat. Assuming the projection system is properly engineered, heat removal should be accounted for, though long term failures may still occur due to long term exposure to the projection lamp beam (due to thermal damage to the driver circuit and not to the mirror itself).

It's no simple science.

airscapes
04-26-2012, 02:01 PM
This article claims 10,000 to 20,000 hours.. a simple goggle will show that it is a common problem.
http://www.av.net.au/contents/issue_3/dlp_tutorial.pdf

If the lamp effected with proper cooling there would be no point..

wootcat
04-27-2012, 06:51 PM
I read that same article, but to me, it looks more like it's referring to the lifecycle of LED's, not the mirrors. You'll note that the article mentions other light sources and significantly shorter lifespans in those sections.

HDTV77041
05-04-2012, 10:56 AM
Check this out

http://www.youtube.com/watch?v=erHUzDulS4c

http://www.howtorepairtv.com