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Alex H. December 15th 04 11:07 PM

retrace lines
 
Hello,

a) My monitor has a greenish picture with retrace lines. I disconnected the
cathode for green, result: no change. A measurement with a crt-meter show's
no problems like hk-short, the emission from green is the same as red and
blue. The focus of the picture is okay, turning the SC-pot (G1 ?) on the
flyback changes the brightness.
When I switch off the monitor i can see green and purple spot in the middle
of the screen.

The monitor is a Iiyama 17" Vision Master 404.


Thanks for your help.


--
Alex.

[email protected] December 16th 04 12:01 AM


Alex H. wrote:
Hello,

a) My monitor has a greenish picture with retrace lines. I

disconnected the
cathode for green, result: no change. A measurement with a crt-meter

show's
no problems like hk-short, the emission from green is the same as red

and
blue. The focus of the picture is okay, turning the SC-pot (G1 ?) on

the
flyback changes the brightness.
When I switch off the monitor i can see green and purple spot in the

middle
of the screen.

The monitor is a Iiyama 17" Vision Master 404.


Thanks for your help.


--
Alex.


First off it sounds like the tube is being overdiven. Have you tried
turning the screen voltage down to see if the retrace lines disappear?
Is the degaussing coil working?


Alex H. December 16th 04 12:41 PM

wrote:

a) My monitor has a greenish picture with retrace lines.


[...]

First off it sounds like the tube is being overdiven. Have you tried
turning the screen voltage down to see if the retrace lines disappear?
Is the degaussing coil working?


Thanks for your answer stokesb,

I have turned a potentiometer named SC (=Screen ?) only to check if there is
a voltage present (picture disappeared). I will repeat it and try to adjust
it. Is the green phosphor more sensitive so that the wrong voltage has only
a effect to the green color ?

Degaussing coil works. The green spot is very small, like a pixel, the
purple one is bigger and one looks more fuzzy. Maybe the size of the
ENTER-Button. A red, (blue, green) test pattern shows no psychedelic
colors :-)

Today I have noticed that the effect is stronger in the moment when the
monitor switch between resolutions.


--
Alex.

Jerry G. December 16th 04 05:13 PM

If the bias voltages are correct to the electron guns, and the blanking
circuits are working properly, then it is the CRT. I have had on a number of
occasions the CRT read okay on a checker, and when the high voltage and
biases are properly applied, it was not in good condition. In some these
cases, I was able to verify this by swapping out the chassis to another set
that has a good CRT.

--

Jerry G.
======


"Alex H." wrote in message
...
Hello,

a) My monitor has a greenish picture with retrace lines. I disconnected the
cathode for green, result: no change. A measurement with a crt-meter show's
no problems like hk-short, the emission from green is the same as red and
blue. The focus of the picture is okay, turning the SC-pot (G1 ?) on the
flyback changes the brightness.
When I switch off the monitor i can see green and purple spot in the middle
of the screen.

The monitor is a Iiyama 17" Vision Master 404.


Thanks for your help.


--
Alex.




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