mlv wrote in message ...
Bob Minchin wrote:

Mike,

are you sure about that model number?
I have a Sony 14" manual here and all the variants are
KV-14M or T1letter according to country of use

The UK model with UHF tuner is KV-14T1U (M indicates a vhf/uhf tuner)

If your set is similar to mine then look out for a 40 pin chip MC44007P
which is the Chroma processor which has a crystal running at 4x the
colour
subcarrier eg 17.734 MHz. One end of the crystal connects to pin 33.

Hi Bob

Yes, the model number is KV-M1420U (S/N: 6043B75). The manual listed three
model numbers, so I took the details off the TV rating plate. I've had the
TV a while, maybe 12-14 years!

This MC44007P chip, is it plug in or soldered? Are you suggesting the chip
might need replacing, or that I should check for dry joints at its pins?
Or
is a faulty crystal more likely? Assuming I have the back off the TV and
am
looking inside, where is the PCB carrying this chip most likely to be
located?

The fault has gone away for the past three days and the television is
working normally with good colour at the moment. I'm sure the fault will
return.

Thanks for your help.
--
Mike
-Please remove 'safetycatch' before firing off your reply-



Hi Mike,

It does sound like you have a model not covered by my service manual. From
memory mine Tv is about 6 years old.
I mentioned the the part number of the chroma processor simply to help you
find the crystal. Once located you could check to see if it is oscillating.
I don't know if you have the right sort of test equipment for this anyway or
indeed would recognise a crystal.

As you say it is now working I would suspect dry joints. I doubt if the ICs
are socketed but if they are, dirt or corrosion on the pins can be an issue.
If you are comfortable with using a fine soldering iron, then reheating
joints in the region of the colour crystal could do the trick.


Try http://www.maplin.co.uk/ and search for Crystal to see pictures of a
crystal - usually silvery metal cans , sometimes with plastic sleeves.

frequency will be a multiple of 4.433MHz either 1x 2x 3x or 4x


HTH

Bob