Sony Trinitron model KV-19TS20

My vintage Sony Trinitron model KV-19TS20 goes wacky after inly a few seconds. screen has jagged lines and makes a noise that changes in pitch from low to high. Can somebody please help me?

Reply to
Glenn Russell
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What have you tried on it so far?

Reply to
rev.11d.meow

Try this first. Pull the chassis and resolder anything that looks suspicious, especially around the hor. output area. Lenny

Reply to
captainvideo462009

Hello, and that sounds like a classic horizontal sweep problem. For whatever reason(s) the horizontal section is not generating the proper sweep waveform and since this section also provides high-voltage to the CRT (Picture Tube), the combined effect is evident on the screen. The high-pitched sound is coming from the vibrating core of the horizontal output (flyback) transformer. The flyback or horizontal output power transistor feeding the flyback could be bad or something else like a cold solder joint(s) might be the issue. Sincerely,

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J. B. Wood	            e-mail: arl_123234@hotmail.com
Reply to
J.B. Wood

If that is like the trinitron that gave me trouble, YES check the Horizontal Sweep Section. The design there seems marginal, runs HOT, and appears to 'kill' the output transistor, but replace its driver too while you're in there. Why? 1. you're in there, and 2. When the output Transistor went, it takes the driver, or at least greatly weakens it. And, Why not rpelace it? What is saved by being cheap? PS: don't know if related, or cause, but one of the blocking caps was leaky and had to be replaced. I found out because the 'fix' of changing only output transistors lasted a few months before all wonky again.

Reply to
RobertMacy

Make sure to resolder the horizontal driver transformer leads. If there is an electrolytic capacitor connected to the H drive circuit, replace it too.

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Reply to
Chuck

Hello, again, and in assuming that the OP still has a properly sized picture with exception of the artifacts at the edges of the screen, what may be occurring is arching due to insulation breakdown in the flyback transformer, high-voltage rectifiers or other components that have to withstand many kilovolts. A strong scent of ozone in the horizontal section might be an indication. Just another consideration in addition to those who previously provided timely troubleshooting tips. Sincerely,

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J. B. Wood	            e-mail: arl_123234@hotmail.com
Reply to
J.B. Wood

What about the bad connections at the coils to the IF chip. Nobody mentioned that.

Reply to
jurb6006

You are right. Also the bad grounds in the tuner.

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Reply to
Chuck

Tuner grounds? You may be thinking of RCA

Reply to
captainvideo462009

Sony tuners were not immune to bad grounds, particularly the combo tuner/IF modules, although they were no where as troublesome as those RCA CTC17X series.

Reply to
John-Del

At the Sony warranty station where I worked there were so many sets returning with tuner ground failures, that it got to the point, regardless of what the set was brought in for, we resoldered the tuner grounds as well as all IF and AFT transformer leads.

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Reply to
Chuck

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