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Question about 634 Negative backlit


New member
I just received my 634 Negative backlit LCD and am attempting to get it to work with a VIA EPIA mini-itx motherboard under Red Hat 7.3. I have sucessfully configured lcdproc and gotten some stats up but my display does not resemble those I have seen on the crystal fontz website nor the review at pimp rig in that it is more of a washed out green on green rather than green on black (this starts in the splash screen). Is this natural or a power issue? I am using the Crystal Fontz backlit power cable, and I have made it look a little better by playing with the backlit/contrast values in LCDd.conf but even at the lowest settings it is still dark green on light green rather that green on black as I had hoped. Any ideas?
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CF Tech

The display should look quite close to the photos.

Typically you would run the backlight at 100% and the contrast somewhere around 50 to 60 for use in typical office lighting.

For use in low-light conditions, reducing the backlight can make the display more readable.

You might want to try using WinTest on a Windows PC to verify operation.


New member
Also having same problem

Im having the same problem with my 634 neg. Has there been a solution found or problem discovered. Thanks



New member
the closest i've found to the pics is like 55% contract and 40% back light.. looks close to the pics