i have a KV-27ts27 made July 1992
I'm noticing that red is more brown than red.
i tried adjusting things a bit but not gotten very good results.
there is no red drive pot. there is a green drive and a blue drive but no
red.
there is a red BKG pot and a blue BKG and a green BKG.

is there a procedure for tuning color? i made a nice colour bar test pattern
on my PC and use the tvout from the PC into the video 1 input.

Wish i could get this set tuned up because it works well other than the poor
colors. there is definately red there so its not a failed gun. at least not
completely.

i have replaced the MPX chip in the past.
any help would be appreciated.
Joust

"Joust" bravely wrote to "All" (01 Nov 05 20:46:28)
--- on the heady topic of "Kv-27ts27 color problem"

Jo From: "Joust"
Jo Xref: core-easynews sci.electronics.repair:347167

Jo i have a KV-27ts27 made July 1992
Jo I'm noticing that red is more brown than red.
Jo i tried adjusting things a bit but not gotten very good results.
Jo there is no red drive pot. there is a green drive and a blue drive but
Jo no red.
Jo there is a red BKG pot and a blue BKG and a green BKG.

Jo is there a procedure for tuning color? i made a nice colour bar test
Jo pattern on my PC and use the tvout from the PC into the video 1 input.

Jo Wish i could get this set tuned up because it works well other than
Jo the poor colors. there is definately red there so its not a failed
Jo gun. at least not completely.

Jo i have replaced the MPX chip in the past.
Jo any help would be appreciated.
Jo Joust


The drive pots are for the colour gain, an analogy can be made to an
equalizer control in audio. Only 2 DRIVE pots tells us that the red
gain is fixed. The green and blue pots are used to match up these
colours to the red (both typically set at about 1/4 rotation). The
drive pots are used to set the colour temperature of the bright white.
The other 3 pots are for setting the bias or the low brightness grays.
These usually set initially about 1/3 but then more or less depending
on the health of the colour guns. A weak gun will require more bias
and more drive. At some point though the internal voltages are upset
and the gun will both not focus, and converge properly, or even bloom.

I have a monitor with a bad video processor. Colours are saturated
with good white and nice gray scale but yellow looks beige as if
it didn't have enough red gain.

A*s*i*m*o*v

.... I worked hard to attach the electrodes to it.

Assuming the user picture controls work properly and the image is not
gray when the color is turned off:

Could be a worn out picture tube that will no longer properly balance
or a failure in the video circuitry. You really need to have the video
output voltages and drive levels checked to confirm that there is no
failure before cranking on controls.

In short, the drives control the high level on the tube and the
background sets the low level.

If readjusting:

Depending on the specifics of the model the drives probably need preset
to mid control for the blue and green to set the base drive levels the
same as the red.

Then turn all three background controls all the way back to minimum.

Apply a black and white gray scale bar pattern on screen. If the set
has a service switch then it needs to be set to give a single line
across the screen.

Turn up the G2/screen voltage until one of the gun colors is clearly
but slightly visible across the screen. If there is no service switch
then the 10 IRD gray bar should be used for the background adjustment.

If it is red or green then the other colors background, red or green,
needs adjusted to make the line yellow. Then adjust the blue
background to make the line as close to white or light gray as
possible.

Turn off the service switch and look at the lightest color of gray
before the white. Adjust the blue and green drive to make the
highlights look as close to gray and white as possible.

Given the age of the set it is probable that the crt will not track
properly from low light to high light gray scale. Get it as close as
possible.

Otherwise it might be helpful to have a technician do the gray scale
adjustment that has lots of experience. They will be able to generally
get it close by eye and fudge the adjustment a little even on a weak
tube to get a watchable picture.

is there a way to know for sure if the tube is bad?
can you measure voltages on the guns or use a scope? I've tweaked these
a lot and got no satisfaction.

another question. since its the red drive that needs turned up can a
pot be added presumably in place of some fixed resistors that set the
red as the ref color.

Yes to the first question.
Take the TV to a service shop that has the CRT testing equipment.
As far as messing with the resistors NO..
Then you will know for sure and then can get on with your life
and replace the TV....After all its only an appliance.


kip
"Joust" wrote in message
oups.com...
is there a way to know for sure if the tube is bad?
can you measure voltages on the guns or use a scope? I've tweaked these
a lot and got no satisfaction.

another question. since its the red drive that needs turned up can a
pot be added presumably in place of some fixed resistors that set the
red as the ref color.