I am trying to locate the actual drive circuit, but makes it quiet
difficult without a schematic and if you don't know wtf you are looking for.

I have done some more testing and found that although i initial get low
readings of Blue = 120VDC, Green =195VDC and Red =195VDC at the
cathodes, if i leave the unit on for about 5mins the voltages are all
the same. But still has a slight red tinge and green is still low.

Now these are the reading from the collector of the drive transistors
and basically and cathode pins to the CRT. On readings i get on the
otherside of the resistors for each gun is about 217VDC constant and
equal between them all.

Now in this unit it looks like the main guns are red and green for
intensity setting and the blue gun separate, as it has a slightly
different circuit layout and components.

TEX


Art wrote:
Blue drive to the video output device may be too high, causing the item to
conduct too heavily, that will eventually lower the voltage because of the
current draw.Check the condition of the video drive and output devices, the
voltages at each device, and the voltage at the video processor ic. Also
check the video signals at each device. Post the diagnostic results so we
can evaluate those parameters and attempt to supply additional relevant
information
"TEX" wrote in message news:1154261584.506828@ftpsrv1...
Are you saying the Blue driven at too a high a voltage? I would have
thought it was too low, or the others too high, causing the imbalance.
I have measured these with the CRT connected to the board and disconnected
with same findings.

wrote:
TEX wrote:
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 need to provide the rest of the troubleshooting voltage and
waveform measurements at the crt for anyone to help.

From the spartan information available, the blue bias or drive is way
too high.