samsung cw28 crt tv - blanking problem?

[b]

Hi there, was wondering if anyone could offer any words of advice on
the following problem:
replaced the LOPTX /flyback in this 100hz tv (S53A chassis), set now
powers up but no picture, only a few strips of white light near the
very top of the screen.

slowly cranking up the screen control brings up a raster, a clear
picture but with visible retrace lines. By backing off on the screen
control at this point, it is possible to remove them, but on power up
once more the set blanks the video.
My question is: is there likely to be a setting in the service menu
which could resolve this or have I got a duff line transformer/some
other component? I have replaced the caps in the 200v feed to the RGB
to no avail.
regards, Ben

 

[Art]

Scope video signals going to the crt panel, check the B+ and G2 levels at
the appropriate test points. Confirm that are no solder splashes, cracked or
open connections. These shutdown problems may necessitate using the service
manuals available from Samsung. Check the feedback circuits into the protect
(OVP,OCP, Etc) may have a flakey diode or transistor, etc, or maybe just
lousy soldering (Manufacturing Induced). .

 

[b]

Scope video signals going to the crt panel, check the B+ and G2 levels at
the appropriate test points. Confirm that are no solder splashes, cracked or
open connections. These shutdown problems may necessitate using the service
manuals available from Samsung. Check the feedback circuits into the protect
(OVP,OCP, Etc) may have a flakey diode or transistor, etc, or maybe just
lousy soldering (Manufacturing Induced). .

Thanks Art, don't have a scope but you've given me a few pointers.
However, there isn't a 'shutdown problem' as such, just that it seems
to me that either the g2 is too high or the blanking circuit is faulty.
-B.