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Discussion Starter · #1 ·
I just picked up a Davis Powerbeam V for my living room, and while I'm pleased overall, the RGB input seems a little muddy, with a very weak red. The on-screen menus have vibrant colors, and the S-video in doesn't have this problem.


I suspected the VGA "buffer cable" as the culprit, so I tried replacing it with a nicer, straight-through VGA cable -- it doesn't work. Upon closer inspection, the signal that the projector expects from the "VGA" input clearly isn't standard VGA; the buffer cable does *something* to the signal, but I don't know what.


Does anyone know what exactly the buffer cable does? I saw posts here about other Davis buffer cables, but they were all talking about EVC->VGA cables for newer model projectors. This one just has HD-15 VGA connectors on it.


For reference, I tried the following:


+ Straight VGA cable from PC->projector. No signal.

+ Buffer cable from PC to SVGA monitor via gender-changer. No signal.

+ VGA->BNC cable connected to BNC->VGA cable to projector. No signal.


I looked at the voltage levels of the HD15 pins coming out of the VGA card vs. the buffer cable, and they're quite different. I suppose I can always keep the buffer cable but cut and shorten the unneccessarily long 5m cable coming out of it to see if that helps...


thanks,

-tbone
 

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Toren, I also have a pbv,however I haven't had any problems with mine.Not getting a signal out of the buffer box to a monitor does sound strange as it just adds the extra wires not used for video to the box for mouse control to the computer from the davis remote thru the projector.I've used both the buffer box and a vga cable and did find some fuzzys with the box in fast paced movies.As far as the reds being weak there is saturation&tint adjustments for the s vid & composite inputs only.vga input omits color change.Just play around in the menu a few times to get well acquainted with where everything is.Hope this helps,if not respond back and I will try to answer more clearly any specific questions if I know the answer.
 

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JVC NX7 Projector, Draper 132" (2.35:1) Techvision XT 1300x, Panasonic DP-UB420, Zidoo Z9x, Zappit
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Hi tbone,

IF, and let me emphasize "IF", the Davis powerbeam uses the same buffer box as the Davis 450 and DL-S8, then the input to your projector is an EVC plug. What you need is a VGA-to-EVC adaptor. I use one with my DL-S8 and it eliminates the buffer box and results in a sharper image. I don't recall which company I got the adapter from, but if you do a forum search under "EVC", you will probably find the threads. It was about 2 years ago when forum member Greesh (sp?...sorry) discovered this. The plug is very specific because the wrong adaptor can, theoretically, result in a power surge and, potentially, damage your projector.

Good Viewing,

John G
 

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Discussion Starter · #4 ·
The projector's connector is a VGA-type HD-15, not an EVC. Dunno what signal they're running over it, but it's definitely a VGA connector.


PTremb, are you saying you've successfully used a straight-through VGA cable to connect the PBV to a HTPC *without* the buffer cable? If so, I wonder what's different about mine.


I also noticed that the monitor pass-through port on my buffer cable box doesn't seem to work; the monitor doesn't see a signal coming through it. I may use that as an excuse to try to get a replacement cable from the seller, and see if it does any better.


thanks,

-tbone
 

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toren, in response,I'm using a video processor which outputs the video to red,green,blue,vert/horiz just like a graphics card.i have connected a 17" monitor to the output directly from the processor and got a great pic.If you would like I can try connecting to my pc to see if the passthru box shows on a monitor to verify everything works correctly.One last thing,this projector wont sync on a signal faster than 75hz,so if you are running your htpc at 85+ it will either not sync or give messed up colors.
 

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In response to adjusting colors on the Davis, see my post here . Bruno used my DavisTuner software to boost the red on his Davis.


You'll need the Davis programming cable.


Mike
 

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mflaster,I have read that thread and would love to do that with the pbv and checked for an upgrade file,however this is a first generation dmd light engine and as such dosn't have the eeprom controling the color pallet/gamma selection.The reason I know this is I have in my possession a demo version from TI that was used to demonstrate to major consumer makers how the unit works and how to implement this technology in new products,(yes it's a full function board,as i tried it in the pbv).I also know that this unit uses the standard video signals as a monitor since digital video didn't start to go mainstream till a few years back when lcd displays started to be sold to consumers.
 
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