On 15 Jul 2005 13:27:03 -0700, "chibitul"
wrote:
Hi, it's me again, the guy who asked here about a vertical image
distortion and I fixed it with your help!
Now, that I gained a little confidence, I wonder if I should tackle
another issue I have in this TV set.
1-the image is slightly distorted, I think the bottom is horizontal but
the top is slightly tilted, maybe 1/4 to 1/2 inch higher on the left
side than on the right side. Yes, it is a trapezoid (I believe this is
how you call this shape in English)
If it was a projection set, especially digital, it is doable if the
right steps are taken. JVC had projection sets a few years back, when
I was still in this business, that allowed owners access to some
adjustments that were traditionally reserved for technicians. I got to
work a lot on those sets, for reasons that should be apparent... :-)
DTV, 20 inch...other than replacing more capacitors in the vertical
section, just to see...don't start adjusting stuff...no good can come
from that, in most cases. Some new sets actually allow that much
deviation as their standard, or close.
2-color fringing: the R, G, B do not overlap very well. From the couch
(9-10 feet away, this is a 20 inch set) it doesn't bother me, but if I
get closer, I see that the B component is slightly shifter UP with
respect to G, and R is slightly down with respect to G (but less than
B). Can I fix this?
Optimum viewing distance is, or was, 4-10 times the diagonal CRT size,
when I was in broadcasting. That's 6' 8" to 19' 6" or so. It is
possible that a convergence adjustment is in order, but, again...this
is tricky with a DTV, even if you have done hundreds of them..
3-finaly, I located the "FOCUS" pot on the back of the high-voltage
transformer. I wonder if I should mess with this, it's an old set and
probably out of focus.
That's one adjustment that is user-friendly...put a mirror in front of
the set, and set it so that the picture is the sharpest. The pot
probably has some glue holding it in place. If you don't use something
similar afterwards it may drift, especially if the set is moved. I
can't remember what we used when I was working at this stuff.
Tom
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