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philips 14gr1236 -- flyback keeps blowing

tv was humming when it come for the first time. I cheked psuply, capacitors, diodos , chokes near flyback, and evertything seems ok. I checked diodes for leaking, but they tested ok. so i replaced the flyback, it had shorted pins 1-10. the new one at2079, lasted 1 second and blows again. Pins 1-10 shorted again. I checked evertything again. What am i missing? I thought flyback was defective so i try with a hr7527, but same thing. crt? socket? any ideas!? thanks?

Reply to
aldo
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You had a problem...you replaced some defective parts, but did not identify the actual cause of the problem, you missed at least one other defective part.

How are the parts that you replaced? Did you use the correct parts when you replaced them? What test equipment do you have?

What do the waveforms look like when controlling the current? What are the voltages going to the flyback? What do you mean by blows again? What are pins 1 and 10, primary, secondary, HV windings?

Why not post the results of standard horizontal output/flyback troubleshooting rather than just the results of throwing the same parts at the problem. Some basic troubleshooting will probably save you much time and wasted parts.

Reply to
dakdak

B+ es about 8V i have checked b+ caps and they are ok i desoldered b+ pin on flyback and still the same b+ voltage I mean pin 1 and 10 on flyback transformer windings. give me some hint about basis troubleshooting, 'cause i am a starter....

Reply to
aldo

this is excellent step by step for beginners:

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and the tv section of
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It is rare for the flyback to short out suddenly like that. the horizontal transistor usually goes first. firstly remove the horizontal transistor and place a 60w bulb across c-e. measure the b+.

test the horizontal transistor. depending on the problem you may need to change: Horiz. transistor and the cap across it's c-e terminals. use exact replacement.

you might want to disconnect secondary loads like the RGB or audio stages to help narrow down the fault.

-B.

Reply to
b

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