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home>>Tech Tips>>Tech tip #1
Marquee Gray Scale Setup
a) Warm up the projector for 30 minutes
b) Set Contrast to 50 and Brightness to 50
c) Go into Service Menu, push UTIL, 9, 0901, 1 (color temp), 2 (6500K)
d) Set Red Drive to 35, Red G2 to 60. Push Enter to continue
e) Set Green Drive to 90, Green G2 to 60
f) Set Blue Drive to 50, Blue G2 to 60
These are typical Drive and G2 (background) levels as found in new projectors. Using the # button, bring up the test pattern of different intensity gray blocks, also called the Stairstep pattern.
g) Look at Stairstep for each color; raise or lower G2 for each color until the second darkest square is just lit, but the darkest square is not lit (lower left corner)
h) Push Enter until all three colors are on. Instead of Enter, if you push Tint you can adjust each color while all three colors are on. Raise or lower Drive for each color until peak whites look okay (bright squares of the Stairstep pattern. The Drive adjustment interacts some with G2 so repeat step g) as needed.
i) Inability to see the second darkest square with G2 below 75 for any color indicates a worn or damaged tube. The need to set Red Drive above 60, or Blue Drive above 75 also indicates weak tubes.
j) If you have a digital voltmeter, take the top gray covers off and try to measure the filament voltage across connector P14 (see PIC 1), it should not exceed 6.50 volts dc when the unit is powered up. P14 is on the mother board just below the cover for the blue neck board. Filament voltage above 6.50 for a few hundred hours will destroy the cathodes in the CRT electron guns. We can repair your LVPS filament power supply alone or as part of our Marquee Fan Noise Reduction mod; e.mail us for details.

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