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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

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Old 5th Feb 2012, 7:49 pm   #21
Francispanic
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Default Re: HMV Stereomaster not playing at constant speed.

Ahh I see what you're saying. Well the fuse itself was broken, and looks as if it hasn't been replaced for some time. There hasn't been any problems with it since the new fuse was fitted, so far so good anyway.
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Old 1st Mar 2012, 12:29 am   #22
Francispanic
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Default Re: HMV Stereomaster not playing at constant speed.

Well, you said this would happen, I replaced the fuse and it was fine for ages, now when ever I turn the thing on it blows a fuse! I might just buy a C.D player. Deary me!
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Old 1st Mar 2012, 11:06 am   #23
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Default Re: HMV Stereomaster not playing at constant speed.

Is the fuse blackened?
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Old 1st Mar 2012, 2:18 pm   #24
Francispanic
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Default Re: HMV Stereomaster not playing at constant speed.

There is a very small black smudge on the inside, the fuse wire itself seems to be completely obliterated. I've turned it on with a view of the fuse itself, it instantly sparks, then the sound gradually turns down to silence.
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Old 1st Mar 2012, 2:31 pm   #25
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Default Re: HMV Stereomaster not playing at constant speed.

If this happened when you changed the speakers, then check your wiring and also the resistance of the new and the original speakers, as it might be something you have done.

This unit does not have any O/P transformers if it's not a valve job, so the wrong speakers or wiring might be giving it problems.

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Old 1st Mar 2012, 5:22 pm   #26
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Default Re: HMV Stereomaster not playing at constant speed.

As Steve says, check over your previous work. The fact that sound appears albeit briefly indicates a partial short somewhere, but if you continue trying to use it the output transistors and possibly other components will end up getting fried.
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Old 2nd Mar 2012, 5:53 pm   #27
Francispanic
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Default Re: HMV Stereomaster not playing at constant speed.

I've just tried turning it on without the speakers connected, and the fuse still blew, does this mean it is definitely a wiring problem? What should I be looking out for if so? I'm a real novice when it comes to electronics!
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Old 2nd Mar 2012, 5:58 pm   #28
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Default Re: HMV Stereomaster not playing at constant speed.

This suggests some problem in the output stage. To be honest, without the schematic and some experience, you'll find it hard to go much further.

You could try disconnecting the transistors from their heatsinks, in case of the old 'tin whisker' type shorts within them. Then power up briefly.
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