Hi,

Thanks to everyone who offered their help.

I managed to get the TV to stay on, although I didn't find out what
actually was causing the shut down. I have Photofact 4968 for this model TV,
but there is no information about IC7200, TDA9577H. I couldn't find a data
sheet for this IC on the web. I suspect it relates to the beam current
sensing circuit or IC7200. Parts tested good and voltage measurements
were right on, or not far from values in Photofact.

I noticed if I increased the brightness with the pattern generator, the
TV starts to go off. I reduced (which were not set very high) the picture
settings such as brightness and picture/contrast, as well as the color level.
Then I increased the "screen" a small amount. Note: I had tried different
"screen" settings before, but that didn't fix the problem.

Now the picture is a pretty good (it was good before), and the TV stays on.
I ran it on and off for a number of hours.

Brad

On Tue, 09 Jan 2007 22:02:07 GMT, in sci.electronics.repair you wrote:

Hi,

I have a Magnavox TV model 27MS3404/17, chassis L01.1UAC-7638
(mfg. 06/05) in my service shop that comes on, picture shows for a few
seconds, then the TV goes "off". Actually the horizontal sweep shuts
down. The SMPS is still "running" at "full power" (Reg B+ is 130V).
Note: The HV was around 27KV with picture showing.

If I use a pattern generator (color bars, cross hatch, etc.), the TV stays
on!!!!! However, with a normal TV signal, it goes off in a few seconds
after the picture shows. With no signal (snow), the TV stays on much longer
but it still goes off. It only stays on with the pattern generator!!!!

Note: I had tried different "Screen" (on FBT) settings.

Any idea what is the cause of this weird problem?

Thanks in advance, Brad

Before you type your password, credit card number, etc.,
be sure there is no active keystroke logger (spyware) in your PC.

These sets tend to have intermittent problems in the H drive circuit. There
is a kit avaialble torepair the problem, which usually becomes worse. Also,
the screen setting is critical and can cause shutdown.

Leonard

"Brad" wrote in message
...
Hi,

Thanks to everyone who offered their help.

I managed to get the TV to stay on, although I didn't find out what
actually was causing the shut down. I have Photofact 4968 for this model
TV,
but there is no information about IC7200, TDA9577H. I couldn't find a
data
sheet for this IC on the web. I suspect it relates to the beam current
sensing circuit or IC7200. Parts tested good and voltage measurements
were right on, or not far from values in Photofact.

I noticed if I increased the brightness with the pattern generator,
the
TV starts to go off. I reduced (which were not set very high) the
picture
settings such as brightness and picture/contrast, as well as the color
level.
Then I increased the "screen" a small amount. Note: I had tried different
"screen" settings before, but that didn't fix the problem.

Now the picture is a pretty good (it was good before), and the TV stays
on.
I ran it on and off for a number of hours.

Brad

On Tue, 09 Jan 2007 22:02:07 GMT, in sci.electronics.repair you wrote:

Hi,

I have a Magnavox TV model 27MS3404/17, chassis L01.1UAC-7638
(mfg. 06/05) in my service shop that comes on, picture shows for a few
seconds, then the TV goes "off". Actually the horizontal sweep shuts
down. The SMPS is still "running" at "full power" (Reg B+ is 130V).
Note: The HV was around 27KV with picture showing.

If I use a pattern generator (color bars, cross hatch, etc.), the TV
stays
on!!!!! However, with a normal TV signal, it goes off in a few seconds
after the picture shows. With no signal (snow), the TV stays on much
longer
but it still goes off. It only stays on with the pattern generator!!!!

Note: I had tried different "Screen" (on FBT) settings.

Any idea what is the cause of this weird problem?

Thanks in advance, Brad

Before you type your password, credit card number, etc.,
be sure there is no active keystroke logger (spyware) in your PC.


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