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Default RCA sound problems

Hi;

I have been approached by an ex-employer about this. Now we all know
that RCA is working with the TV stations etc., about this, but have no
real answer.

From what I have read there is apparently a problem with the stop bit

in the guide plus data. It is not only a sftware problem on the sending
side, it can also happen when the customer changes channels. This data
problem or something similar has caused issues in other sets from what
I hear as well.

I am ready to throw this baby out with the bathwater, that is not the
whole TV, just guide plus. It should be possible to just interrupt the
data period. This is of course optional to the customer, would you
rather have an onscreen TV guide and no sound, or buy a newspaper. If I
were the customer I would take nothing, just see what's on.

Any insight on exactly how the data gets in would help, or perhaps I
might find it in an RCA training manual. It might be as simple as
cutting one jumper, actually it probably is.

Another question I would pose is what percentage of people will opt to
disable guide plus ? The ex-employer who contacted me has a large
percentage of older customers some of whom would have a hard time
reaching down to unplug things. There are also situations where people
channel surf alot, this could also become a nuisance to say the least.

Anyway, IIRC all this data is in the VIR, and I don't remember right
now if raw video is sent to the micro or what to accomplish this. If it
needs the raw video then a clamping circuit driven off vertical
blanking might be necessary.

Hah ! I just had a thought, there is a slight possibility that
something like this might eliminate the closed captions as well, hehe,
I doubt many deaf people are calling us about this problem ! lol. Nice
little joke, but realistically deaf people have friends and family who
can hear, and indeed they payed for picture, color and sound. That is
still the definition of a television. While the word doesn't literally
mean that sound is included, it is generally assumed. Don't want sound
? Buy a monitor.

I'm going to familiarize myself more with the guide plus system, at
least in the CTC195. Any tips would be welcome.

By the way, about CTC195s, if you get an aftermarket flyback that
produces black vertical lines in the left side of the picture, the fix
is a 10K resistor to ground at the H pulse input pin of the jungle IC.
I don't remember the pin # right now but it's findable. It's the pulse
resistively divided from the HOT collector. Done three of them so far
and no callbacks, HOT runs cool, geometry is good. ( might be pin 12,
but look first )

In some cases we techs need to remember the basics; picture, color and
sound. This is no worse than jumping out a Mits PIP module or replacing
a Hitachi 3DY COMB filter with the single line version when it is in
too bad of shape to fix. (there is a certain mod you need to get
vertical sync, but I have done it).

One day I'd like to get a database together of all the modifications,
and I don't mean the factory ones. For example one of these days the
STK4274 will be discontinued. Therefore, we need to know how to use the
STK391-0X0 in it's place. If the STK is clamped in place this is a
piece of cake, but if they use the screw holes there are issues.

Any other neat mods out there ? I am always interested, can't get this
part eh ? HEH.

JURB