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Last week my BenQ PB6110 projector started displaying wide (5-10% of picture height) horizontal bands of darkness that slowly (2 seconds from bottom to top) scroll upwards on the screen. There is no lines visible on the pre-picture blue screen. The bulb has 2100 hours on it. We planned on buying a new bulb when our budget permitted when we noticed the picture degradation starting about six months ago. The same DVDs played from the same player has no bands on our TV. I hope the dark bands are connected to failing bulb and not something more serious. I'd feel ripped if I bought a new bulb only to discover that my projector needed another fix to correct the banding. Any ideas or advice?

I noticed that our local Costco has a sub-$900 Optoma. Way to go if my BenQ is hooped.

thanks
 

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Scrolling bands are almost always some sort of Ground Loop issue. If this is happening on cable signals, then your cable coming into the home is not properly grounded. If it's happening on other signals, then one or more of your pieces of equipment are not properly grounded. Search this forum for "ground loop". You'll find several previous threads on the topic. Here's a sample:

http://www.digitalhome.ca/forum/showthread.php?t=77171&highlight=ground+loop


It's also possible that you're encountering a form of Macrovision copy protection. If you can provide more details of what you're watching, what's connected to what and how (all makes/models, etc) then we can assist further.


Here's a post useful for those new to the forum - Search Tips, FAQs, Optimization, etc:

http://www.digitalhome.ca/forum/showthread.php?t=57741
 

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It could also indicate a poor video cable connection (often related to a ground loop) or power supply problem in the projector. Re-seat the video cables and make sure there is no sign of cable damage at the connector. You can test the projector by isolating the equipment. To do this, unplug the cables from the projector and DVD player. Then connect them using an separate cable. If the bars are still there, it indicates a problem with the projector. If they are gone, it indicates some other problem, such a cabling or a ground loop. The ground loop can be isolated by connecting or disconnecting cables one at a time. The cable that makes the bars appear or disappear is a source of the ground loop. (There are usually two but it is only necessary to eliminate or isolate the outside source.) As already mentioned, ground loops are often caused by outside cables entering the home, such as cable TV. If the problem is in the projector, it can usually be fixed easily by a local repair shop.
 

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There is no lines visible on the pre-picture blue screen
That is helpful since it seems to tell you the light engine/color wheel is working properly. I would try the other inputs (audio and video) on the PJ as already suggested. I saw a TV once that did something similar and you had to wiggle the connectors to get a clear image. I changed the input and it fixed the problem. At first I tried to re-seat the cable but the problem was inside the TV. They were ready to junk the TV too.
 
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