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Chapter 5---Electronics
8.Reinstall the Convergence/Deflection PCB by lowering the right side in first until it clears the electronic module edge, then lowering the left side in.
NOTE: It may be necessary to fit the top 2 fins of the heat sync over the electronic module frame lip at the left to get enough clearance for the right side to be installed. Carefully fit the board over the mounting screws and slide the PCB into position. Tighten the screws and reconnect the connectors.
5.8Scan Reversal PCB
Scan Reversal PCB - Main Functions
!Reverses of scan in both horizontal and vertical axes
!Outputs deflection waveform to the Deflection Yokes on the CRTs
!Outputs convergence data to Convergence Yokes on the CRT
!Horizontal width adjustment for each color (R, G &B)
!Scan failure detection for (horizontal and vertical) deflection amplifiers
Scan Reversal PCB - Inputs
H_OUT_FLYBACK - output horizontal deflection waveform from the Horizontal Vertical Deflection PCB (about 800 Vpp).
H_LOCK (pos.) - horizontal interlock for the yoke connectors from the Horizontal Vertical Deflection PCB (about 5 V when closed, 15 V when open).
H_RGB (pos.) - return of horizontal deflection waveform to the Horizontal Vertical Deflection PCB.
V_RGB (pos.) - output signals of red, green, and blue from the Vertical Amplifier of the Horizontal Vertical Deflection PCB (about 40 Vpp).
X_RGB (pos.) - output signals of the red, green, and blue from the Horizontal Convergence Amplifier for the
Y_RGB (pos.) - output signals of the red, green, and blue from the Horizontal Convergence Amplifier for the
±15 V - input power from the Horizontal Vertical Deflection PCB for the analog circuitry.
+5.1 V - input power from the Horizontal Vertical Deflection PCB for the digital circuitry.
From Yokes
H_RGB_YOKE (neg.) - bottom of red, green, and blue horizontal deflection yokes.
V_RGB_YOKE (neg.) - bottom of red, green, and blue vertical deflection yokes.
X_RGB_YOKE (neg.) - bottom of red, green, and blue
Model 250 Service Manual |