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Prima 27 inch tv.

model number Q 2770 lack of red on the screen, replaced the crt board,
with one from a working tv, but after finding r 936 open (220 ohms),
picture is still lacking red, & I ca't find any resistors open, or
leaky, or shorted diodes, or drive transistor. What could it be?
Thanks for your time, Robin.
 
A

AJ

Jan 1, 1970
0
Take a 68k resistor and ground the red cathode, screen should go red with
retrace. If not you have a bad crt. Then trace the signal back from the red
output devcie to the video processor is to determine if indeed you are
getting red video bias and drive from that area. Good schematic and scope
will assist greatly.
 
thanks for the help but the CRT board IS bad, the unit works fine with
a test one from a working set and the pix tube is fine.
I can't find what's bad on the crt board, except the 220 ohm risistor.
Robin.
 
J

JANA

Jan 1, 1970
0
If the 220 ohm resistor is bad, did you change it yet? Check the driver
transistors on the board. If it is an IC that does the drive, change that
also.

--

JANA
_____


thanks for the help but the CRT board IS bad, the unit works fine with
a test one from a working set and the pix tube is fine.
I can't find what's bad on the crt board, except the 220 ohm risistor.
Robin.
 
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