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James Thompson James Thompson is offline
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Default TV Missing color diagnosis


"TEX" wrote in message news:1154258261.420666@ftpsrv1...
Been working on this 29" TV and cannot work out why the voltage on the one
of the driver transistors is low. Drive transistors located on the CRT
neck board.

Blue =120VDC
Green =195VDC
Red =195VDC

Green does show up on the screen but very dull. Red/magenta hue. Am i
correct to say that the blue it under driven causing the complementary
color to produce the hue. Or are the other two guns over driven????

Since there is green am i to assume there is nothing wrong with the RGB IC
and it is still just a driver circuit problem

Where to diagnose from next??? Just stuck on this cos never come across it
before.

Thanks

TEX


You can see if it may be a driver problem by switching color drive feed
wires to the crt board. As in switch the red with the green and see how
bright the color is driven. This may eliminate the problem from the color
output from the chassis and you can concentrate your effort to the neck
board. If the green is bright after switching with red driver, then you
will know the green driver is weak (not the output on the neck board). Jtt