| Author |
Message |
Dmitry Teytelman
Guest
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 Posted:
Mon Feb 07, 2005 5:33 am Post subject:
Problem with Sony KV-32FS12 TV |
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Hello,
I am trying to figure out a problem with a Sony KV-32FS12 TV (BA-5
chassis). When I got the set it had a blown HOT. I replaced the transistor,
run the TV for a few seconds and saw arcing in the flyback (around the
G2 pot). After replacing the flyback the set seems to work fine except for
one problem. The horizontal size is not well controlled. The picture is too
wide horizontally (service mode HSIZ adjustment does not bring it back
fully). In addition bright areas in the picture cause the horizontal size to
decrease. With bright white the bowing very dramatic around 1/5 to 1/4 of
the screen width. The drive signals to the HOT seem to look OK, but I can
see the variation in amplitude vs. the vertical sweep position.
--
--
Dmitry Teytelman (dim@slac.stanford.edu)
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Dmitry Teytelman
Guest
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| Posted:
Mon Feb 07, 2005 4:25 pm Post subject:
Re: Problem with Sony KV-32FS12 TV |
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In article <geoe0190gg3i4h22jec4qeub93u7qjofpo@4ax.com>,
Alan Harriman <vtech@usol.com> wrote:
| Quote: |
Did you use original Sony parts. I've seen a few aftermarket replacements
cause similar problems. Also, how's the 135v supply?
|
Yes, the parts were ordered from Sony. As for the +B supply, it is very
stable, I cannot see any variation.
--
--
Dmitry Teytelman (dim@slac.stanford.edu) |
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Alan Harriman
Guest
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| Posted:
Mon Feb 07, 2005 6:43 pm Post subject:
Re: Problem with Sony KV-32FS12 TV |
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| Quote: | Hello,
I am trying to figure out a problem with a Sony KV-32FS12 TV (BA-5
chassis). When I got the set it had a blown HOT. I replaced the transistor,
run the TV for a few seconds and saw arcing in the flyback (around the
G2 pot). After replacing the flyback the set seems to work fine except for
one problem. The horizontal size is not well controlled. The picture is too
wide horizontally (service mode HSIZ adjustment does not bring it back
fully). In addition bright areas in the picture cause the horizontal size to
decrease. With bright white the bowing very dramatic around 1/5 to 1/4 of
the screen width. The drive signals to the HOT seem to look OK, but I can
see the variation in amplitude vs. the vertical sweep position.
|
Did you use original Sony parts. I've seen a few aftermarket replacements cause
similar problems. Also, how's the 135v supply?
Alan Harriman
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Jerry G.
Guest
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| Posted:
Mon Feb 07, 2005 8:54 pm Post subject:
Re: Problem with Sony KV-32FS12 TV |
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Change the flyback, and HOT. Use original Sony parts only!
--
Jerry G.
======
"Dmitry Teytelman" <dim@teytelman-pbdsl1.Stanford.EDU> wrote in message
news:cu6ujf$p1e$1@teytelman-pbdsl1.Stanford.EDU...
Hello,
I am trying to figure out a problem with a Sony KV-32FS12 TV (BA-5
chassis). When I got the set it had a blown HOT. I replaced the transistor,
run the TV for a few seconds and saw arcing in the flyback (around the
G2 pot). After replacing the flyback the set seems to work fine except for
one problem. The horizontal size is not well controlled. The picture is too
wide horizontally (service mode HSIZ adjustment does not bring it back
fully). In addition bright areas in the picture cause the horizontal size to
decrease. With bright white the bowing very dramatic around 1/5 to 1/4 of
the screen width. The drive signals to the HOT seem to look OK, but I can
see the variation in amplitude vs. the vertical sweep position.
--
--
Dmitry Teytelman (dim@slac.stanford.edu) |
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Dmitry Teytelman
Guest
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| Posted:
Sun Feb 13, 2005 8:08 am Post subject:
Re: Problem with Sony KV-32FS12 TV |
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In article <cu6ujf$p1e$1@teytelman-pbdsl1.Stanford.EDU>,
Dmitry Teytelman <dim@stanford.edu> wrote:
| Quote: |
I am trying to figure out a problem with a Sony KV-32FS12 TV (BA-5
chassis). When I got the set it had a blown HOT. I replaced the transistor,
run the TV for a few seconds and saw arcing in the flyback (around the
G2 pot). After replacing the flyback the set seems to work fine except for
one problem. The horizontal size is not well controlled. The picture is too
wide horizontally (service mode HSIZ adjustment does not bring it back
fully). In addition bright areas in the picture cause the horizontal size to
decrease. With bright white the bowing very dramatic around 1/5 to 1/4 of
the screen width. The drive signals to the HOT seem to look OK, but I can
see the variation in amplitude vs. the vertical sweep position.
|
Here is a followup to my own post - I fixed the TV set! Thinking about the
problem for a while I decided that the EW compensation voltage was too
large, most likely because the HV current was measured incorrectly. Looking
at the schematic I decided to check the circuit from the ABL pin of the
flyback. Checking the components I found R532, a part of the resistive
divider. That resistor was supposed to be 4.7k and measured at 16k.
Replacing that part improved things, but there was still some distortion
remaining. Following the signal path I found R530 to be 57k instead of 18k.
Replaced that - better, but still some distortion. Finally I checked C530 -
the capacitance was about right, but the resistance measured at 330k.
Replaced that - and voila! Geometry back to normal!
--
--
Dmitry Teytelman (dim@slac.stanford.edu) |
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