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Sony KVR21, Many Horizontal white lines on screen?

 
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FRick



Joined: 23 Feb 2006
Posts: 7

PostPosted: Thu Feb 23, 2006 4:30 pm    Post subject: Sony KVR21, Many Horizontal white lines on screen? Reply with quote

This was Sony TV Model KVR21, 5 years old, it is working fine 'till one day when i turn ON, it shows good picture in 10 minutes but after 10 minutes it shows this many horizontal white lines on the screen. I turn OFF and turn On after few minutes but still the same.

Any idea?
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tryme345



Joined: 01 Feb 2006
Posts: 4
Location: Canada

PostPosted: Sat Feb 25, 2006 7:07 am    Post subject: Reply with quote

try tapping the neck of the piucture tube if this changes then you have a bad tube,.if not try the video out put transistor or ic which ever it may have,.or they y buffer which is the video transistor,.carl if i can be of further help contact me at ,[email protected]
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i need information on as PANASONIC color t.v model CT-32G12CV,the set has low power supply and i need the diagram if possible, thanks carl
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PostPosted: Mon Feb 27, 2006 2:34 pm    Post subject: Reply with quote

You are talking on the secondary voltage? I mean after the transformer? Sorry i don't have schema for CT-32G12CV but i can share to you my observation in troubleshooting some power supply.
I hope you can be able to fine the voltage sense pin of the regulator IC or Base of Regulator transistor. Using The Datasheet of the regulator IC/transistor, you can identify the pins and at least know the right switching voltage of this parts. Measure the actual voltage in this pin and compare to the Datasheet, If the actual voltage that you can measure at this pin is lower than the switching voltage specified on the Datasheet, then you need to check the parts that were connected before this pin, it can be a leaky transistor, diode or a change value of resistor, that is not delivering the right voltage so you are getting low voltage on the actual voltage output...... OR it could be on the regulator itself. You can also check big resistor on the AC input, (usually before rectifier) for change value or partial burn, (seldom but have already seen few)

_____________:>
I will try your suggestion on Saturday since I’m in office during weekdays. thanks. its just my first time to encounter this kind of trouble.
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GUEST
Guest





PostPosted: Tue Feb 28, 2006 8:55 am    Post subject: Reply with quote

If the lines are bunch up on top and very stable, you could have a bad
cap on the vertical circuit. if lines are running across the screen it could
be noise. Be more specific.


Yours Truly
Guest
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haljones
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PostPosted: Wed Mar 01, 2006 11:33 am    Post subject: white lines on screen Reply with quote

Is your video washed out, faint or has your brightness increased? If so, try tapping the neck of the CRT with a screwdriver handle while set is playing. Sony has a history of bad picture tubes and this procedure will usually pinpoint the problem for you if it is defective.

Good luck....Hal
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FRick



Joined: 23 Feb 2006
Posts: 7

PostPosted: Thu Mar 09, 2006 1:56 pm    Post subject: horizontal lines Reply with quote

I have tried tapping the tube before but doesn't work, i tried repalzing the horizontal out (damper diode transistor) but no effect. This lines are slightly diagonal, one is going down to right which is brighter and the other is going to left which is a bit dull in color, the line are in green colors now about 1/8 inch. I tried also adjusting the horizontal sync but the lines will just go short on the center but still there, i already tried replacing the color driver transistor on the picture tube circuit board but no luck. The sound i okay, the picture is abit washout in color but can be adjusted in the plyback screen.

pls. help!!!
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