Amplifier cutting out

My technics am/fm amplifier keeps cutting out after ~15 minutes. I only use it with the tuner (having disposed of the CD and cassette players) Power is restored with a traditional tap on the amplifier case or by switching off and back on immediately. Before I go poking about in the case does it sound like a loose connection or faulty component. I could trace a dry joint or similar, but more than that - well no. Any tips?

Reply to
Jim S
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Check for speaker cable shorting strands. See how hot the main heatsink is when it cuts out

NT

Reply to
meow2222

Check any external connectors for integrity.

When it cuts out, does it appear to lose power, or signal - in other words do any power LEDs/lamps go out, or do you merely lose the audio?

Does it cut out with a click, or does the audio just vanish?

If the "cutting out" consistently occurs n minutes after switch-on it suggests overheating of some part, but whacking it back into action negates that suggestion. After your corporal punishment to the amp does it again cut out after 15 mins?

Reply to
Frank Erskine

Dry solder joints tend to develop where there is heat, vibration, or a combination of both. So check transformers, inductors etc first, then power transistors.

Reply to
Dave Plowman (News)

Already did

The led on the amplifier is ON when the power is OFF. When it cuts-out the light does not come back on.

Just vanishes

Yes

Reply to
Jim S

So the psu has shut down.

The fault could be in psu or amp, and its not clear what's causing it. You need electronic skills really.

NT

Reply to
meow2222

then its something IN the audio path = probably an OC capacitor with a dry joint or something - rather than the amp in toto cutting out as a power issue

More than ever dry joint id say.

Reply to
The Natural Philosopher

Speaker delay relays usually, I have a Denon like this, of course remove case and remove relay case clean and find for another 6 months or so.

Brian

Reply to
Brian Gaff

Sounds like a dodgy relay to me.

Brian

Reply to
Brian Gaff

Just treated myself to one of these as space was an issue. Hooked up to a pair of speakers I had lying around. I'm no hi fi buff but they sound pretty good to me, and reviews are generally positive

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Reply to
stuart noble

Or they are also there to protect the speakers from a DC offset. Which could exceed the limit as the amp warms up.

Reply to
Dave Plowman (News)

Always ~15 minutes, even after a power-cycle (or tap) to restore functionality when the amp is already warm?

Reply to
Jules Richardson

The times were approx, but I'll try to remember to do it next time

Reply to
Jim S

Ah! I was right and the first cut-out came after 15 min 11.9 sec then ....... it's not cut out since, now running at 1 hr 11 min - that's not usual tho'

Reply to
Jim S

I can't see any basis for that at all. I've long lost count of the amps I've heard that don't click or thud on power down.

NT

Reply to
meow2222

heard that don't click or thud on power down.

yes, but this is NOT power down, is it?

Reply to
The Natural Philosopher

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"The Tone defect button ..."

I've owned "hi-fi" like that.

Reply to
Huge

Do those poor joints generally show? Just fixed a VCR where the problem was dry joints at a power IC in the SMPS - they all had beautiful 'rings' on them.

Reply to
Dave Plowman (News)

heard that don't click or thud on power down.

Your reason for concluding that would be?

NT

Reply to
meow2222

Took off case and it has been running for 3 hours uninterrupted.

Reply to
Jim S

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