There may be a cold solder joint(s), in the video processing or CRT bias
paths to start with. The changing of the brightness may be the high
voltage multiplier. In your set, it is most likely integrated with the
flyback transformer, and all are replaced as a module.

You can try to rotate the G2 or bias pot back and forth a little in case
it is sitting on a sort of intermittent spot, but more than likely the
HV multiplier section is bad.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
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"William R. Walsh" m
wrote in message news:YFb8b.420878$Ho3.67141@sccrnsc03...
Hello all...

Model number RAC128WA03, marked as being made by North American Philips
in
Knoxville, TN. Says "Sylvania" on the front panel.

This is a set I keep on my porch...and when the weather is bad, the set
comes indoors because the porch is enclosed but unheated and uncooled.
It is
a nice little table set in good condition and it has been kept pretty
clean
over the years.

Problems:

The picture occasionally becomes sort of a soft but pronounced cyan
(blue)
in color. The shift isn't so bad that all other colors are forced away,
but
some colors simply do not appear. When the color control is turned
completely off and a black and white picture is displayed, the syptom
still
appears in a way that seems to shift color temperature. This is
something
the set only started doing recently and a hard whack on the side may or
may
not fix it. At the very least it will produce an attempt at switching to
the
proper colors. I reckon this is bad solder or marginal parts more than
anything else. Is there anything specific I should be looking for?

The next problem seems perhaps a bit more serious and certainly affects
viewability more than the first problem. Periodically the set acts like
the
screen (G2) control on the flyback is being slowly turned up just until
white lines appear softly on the screen. Along with this effect, the
picture
on the screen will get brigher and brighter. After a second or so of
displaying the bright picture with faint white lines, the set reverts to
a
normal picture and the process happens again. I'd say it is repeated
about
every 5 seconds. This problem never goes away as long as the set is
powered
up, but it won't start until the set has been running for --say-- 30
seconds.

I have had very good performance from this set, and I like the way it
looks
and works, so I'd like to repair or get an idea of what is wrong if at
all
possible. Thanks in advance to anyone who can give any ideas or
thoughts!

William