Amplifier cutting out

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

NT

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?

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.

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

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

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.

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

Sounds like a dodgy relay to me.

Brian

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

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

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

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

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'

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

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

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

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

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.

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

Your reason for concluding that would be?

NT

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