Prima PS-42D8 B Service Manual page 29

Failure with resistor rows R415, R418, R422, R424, R429, R430，which may
lead to loss of corresponding color from the gray degree corresponding to
the picture of channel DVI.
Failure with resistor rows R342, R343, R344, R345，which may lead to loss
of corresponding color from the gray degree corresponding to the picture of
sub-channels TV/AV/YCRCB, or lead to abnormal brightness.
Failure with resistor rows R207, R208, R209, R210, R211, R212 or R145,
R146, R147, R148，which may lead to loss of corresponding color from the
gray degree corresponding to the picture of main channels TV/AV, or lead to
abnormal brightness.
Bad connection between N203 and N204, which may also lead to abnormal
picture (column bar like) in main channel TV/AV.
Abnormal picture vertically or horizontally (bar like): Abnormal in complete line
extending all the way from up downward on the screen of stand definition TV setr;
abnormal vertically on half screen of high definition TV set. They may be caused
by the damage of the address BUFFER module that directly corresponds to its
position, or may be caused by the damage of the connection wire that directly
corresponds to the position of the screen. The horizontal bar like abnormality is
also related to the Y driving circuit that corresponds directly to its position. To
judge these phenomena, It's possible to check it by setting the screen to the
status of self check as explained above
No brightness in the square block area: Normally it's caused by the damage of
the address BUFFER module that directly corresponds to its position, or may be
caused by the damage of the connection wire that directly corresponds to the
position of the screen. To judge these phenomena, It's possible to check it by
setting the screen to the state of self check as explained above
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