XOCECO PS42K8, Service Manual

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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
Diagnosis for Plasma Screen of PS42D8
And Maintenance of the Functions of Various Modules on Screen
As shown in the figure below, PDP screen can be divided into power supply board, X driving board, Y
driving board, logic board, logic BUFFER board (E, F, G), Y BUFFER board ( upper and lower), COF
etc.:
* Power supply board : to supply power for the screen, other functional modules on the screen,
our own main board, and video frequency processing board.
Power supply board X driver board
Ydriver board
Logic board
Logic
BUFFER(E)
Logic
BUFFER(F)
Logic
BUFFER(G)
Y BUFFER(up)
Y BUFFER(down)
COF
（
7 blocks
）