tv blows fuse

hi folks i'm new to this forum and have a question . i have a sylvania srt2127s that blows the fuse as soon as i plug it in. I just started messing with busted tv's as a hobby because i recently had surgery for a work related accident and needed something to keep my mind and my hands busy. I just fixed an old sanyo that just needed a couple of capacitors and now i'm trying my luck with the sylvania.please talk in layman's terms as i am not tech educated. pictures or diagrams of parts to check or replace would be very helpful. thanks,wish me luck!

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Steve45
Reply to
Steve45
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Hi, Your description indicates a "primary-side" failure, in other words, the side which is not galvanically isolated from the mains and need great focus to not kill yourself during repair. A wild guess, would be a shorted input rectifier or a shorted switching transistor in the TV's switchmode powersupply. I've even seen damaged mainscords with internal shorts! Maybe a dog chewed on it. This would of course lead to a fuse blow before pressing mains switch on the set. I'm not familiar with this specific set, but that's general TV tips.

Good luck!

--- Steve

Reply to
powerampfreak

Well assuming he's in North America, the mains plug is not fused. The only circuit protection we have here aside from the fuse in an individual piece of electronics is the 20A breaker on the branch circuit.

Reply to
James Sweet

I would agree with this basic diagnosis, and would also seek to reinforce the advice regarding safety. If you are new to this, you absolutely MUST gain some understanding of the dangers of switch mode power supplies, and I would strongly recommend that you do some internet research on this aspect first. They honestly are potentially lethal in inexperienced hands, and can still give you a VERY powerful shock, even hours after they have been switched off, with some fault conditions. You might like to cover your eyes, or turn your head away when you switch on, also. It is not at all uncommon to have the chopper transistor explode its side off, or the wrong type (glass) fuse shatter explosively. If you are intending getting to grips with these, I would recommend at a minimum, fixing yourself up with a proper bench isolation transformer, to offer yourself at least a degree of personal safety.

Arfa

Reply to
Arfa Daily

- D=F6lj citerad text -

I believe he means the internal fuse in the set, don't you think?

Reply to
powerampfreak

I agree with the other posts in this thread. May I add that a quick initial test might be to disconnect the degauss coils from where they plug into the circuit board (they're the loop of plasticky wire going round the back of the tube near its perimiter). power up and see. you may need to replace the 3 legged (or sometimes 2) posistor. incidentally, it is advisable to wire a 100w bulb in series with the mains input - over the internal fuse maybe. if it shines you still have a dead short; if not then you're probably OK, that way you save fuses.

-B.

Reply to
b

Well I'll wish you luck with your recent surgery as I'm going through the same thing myself but when it comes to repair, skill and knowledge usurp luck. Look in the power supply (smps)for shorted diodes or switching transistors. Be warned that to the novice like you, an smps can be dangerous and possesses potentially fatal voltages.

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Reply to
Meat Plow

Dölj citerad text -

Yes, I'm pretty sure he does. I was replying to another response to his post.

Reply to
James Sweet

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