Output Waveforms
Conditions for the color wheel output waveforms of figure 15:
1. These three waveforms appear right after the color wheel rotates (channel 1) and
the TV powers on (channels 2 & 3).
2. The amplitude of the channel 1 Color Wheel signal (180 Hz) is 5Vp-p, but the
data and clock signal output (channels 2 & 3) are at 3Vp-p only.
Color Wheel Output Waveforms into Microprocessor
Waveform Description Voltage
Frequency
Location
Channel 1
Color Wheel rotation pulses
5 Vp-p
185 Hz
L2/pin 3
Channel 2
I
2
C serial data
3 Vp-p
16.3 Hz
L2/pin 4
Channel 3
I
2
C serial clock
3 Vp-p
16.3 Hz
L2/pin 5
Time base = 10ms/div.
data
clock
Rotation pulses
Figure 15 - Color Wheel Output Waveforms
Color Wheel Adjustment
If the color wheel assembly is replaced because of picture noise, picture solarization
(see Video Signal Flow), or TV shutdown, the TV must be adjusted. The bursts of RGB
video must be synchronized to the rotation of the wheel colors. Use the remote control
to enter the extended service mode (figure 16) and perform the adjustments (shown in
figure 17). The adjustment is correct when the service mode pattern displays a solid
color in all of the three colors tested.
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