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Power switch problem

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Power switch problem

Postby SoundHarmonyMKII » 23 Jun 2012 23:37

My Rotel RP-850 belt drive, full manual tt creates a loud pop in my speakers every time it's powered down and occasionally when powered up too.

It started as an intermittent problem when turning the power off, most of the time it would pop but then other times it wouldn't. Sometimes I would also hear a pop when I turned it on but much less often.

Today I decided to start using my NAD PP 3i phono preamp again because it better matches the loading for my cartridge. Now the problem occurs every time it's powered down and it's much louder! It does not send my power amp into protect mode though. :? It also occurs a lot more often when turned on, but it's a much quieter pop. It seems unaffected by turning the volume down, and to occur at all frequencies because if I turn the speakers off I still hear it in my sub.

Please help!
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Re: Power switch problem

Postby paul401 » 24 Jun 2012 09:49

Hi,
would think one of two things here, there might be a capacitor fitted to suppress the switch noise and this may have failed or the switch itself may have become faulty.
There's a service manual in the VE library, hopefully you'll be able to read it ok! Sadly for me this ones coming up with random characters - will have to go and update Acrobat. :)

The cap is a cheap fix and any suitably rated switch would do the job, finding one that's an exact fit/replacement may be a little trickier. Post a pic and someone may identify a supplier.

Paul
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Re: Power switch problem

Postby SoundHarmonyMKII » 26 Jun 2012 01:37

Thanks :)
I have looked at the service manual and noticed that there is a noise suppressor cap attached. No specs are given though, only a Rotel part no., which I'm guessing isn't that helpful for a 30 yr old unit. Since I don't have any experience with soldering I'll have to take it to a shop, so thank you very much for this confirmation :)
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Re: Power switch problem

Postby paul401 » 27 Jun 2012 14:51

Hi,
the value is usually printed on the cap so the technician can take it from the old one. In truth the cap rating probably isn't too critical, just so long as the voltage rating is right.
It's a simple job so shouldn't cost too much either. :)

Paul
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