Amp Problem

Scubadevils

Having a very annoying problem with my amp that someone may be able to shed light on. It keeps cutting out, basically like a click sound from the amp and the sound goes...it doesn't power off though and it clicks back in after a few seconds. The click is the same as what you would hear when you first switch on an amp. Not that it matters (but in case it does), my amp is a Marantz PM7200. Out of warranty too so nowhere to bring it to Its intermittent and for the last hour its probably done it about 10 times with about 20 mins being the most play without interuption. Setup is just a CD player connected via standard phono cables and Jamo speakers which have a lower wattage than the amps output.

Any thoughts? Thanks!

Sparky

Oddly enough I heard that this problem can happen if the amp is on for a while and as a result cuts out due to overheating caused by a loose connection inside the amp.
Best bet is to bring it to a repair shop.

Scubadevils

Cheers Sparky, probably best get it seen to. It actually happens straight away when powered up so not an overheating problem. Plan to replace once my SSIA's come through next year but would still like to keep for another room. On that note, for pure music listening am I better buying a stereo amp as opposed to a 5.1? Not that bothered about home cinema really but if there is an amp not too expensive that serves both purposes I may as well go that route.

mossym

check none of the wires on your speaker connections on the back of the amp, or at the speakers themselves are touching..

in fact, disconnect all speakers and try the amp..if it doesn't switch off one of the speakers is causing the problem..hook them up one by one and see which causes the problem..

no need to take it for repair until you try this

ZENER

That won't necessarily confirm speaker problems, without speakers there's no load on the amplifiers output stages hence no power dissapated to cause overheating.

It's best to bring it to a repair shop as all you'll get here is speculation and best guesses - albeit based on experience - but electronics is never that simple.

Edit: This amp operates in either Class A (25W) or class AB (95W@8ohm - 125W@4ohm) Which mode do you prefer with it ? Class A consumes power regardless of speakers (so my apologies to the previous poster) so in this mode there will more than likely be a thermal cutout circuit and current monitoring. Either way it needs checking out but it might be one more bit of info you can give the repair shop ?!

ZEN

Scubadevils

Thanks for the replies. I tried disconnecting all cables but no joy. One thing since yesterday though is that I left the amp powered on all night and when I tried today it played for about a half hour without any problems - that was as long as I had it on though so may have just been lucky. Zener, I operate the amp in class B mode.

Any thoughts on a good repair shop in the Dublin area?

Thanks again.

mossym

ZENER wrote:

That won't necessarily confirm speaker problems, without speakers there's no load on the amplifiers output stages hence no power dissapated to cause overheating.

It's best to bring it to a repair shop as all you'll get here is speculation and best guesses - albeit based on experience - but electronics is never that simple.

Edit: This amp operates in either Class A (25W) or class AB (95W@8ohm - 125W@4ohm) Which mode do you prefer with it ? Class A consumes power regardless of speakers (so my apologies to the previous poster) so in this mode there will more than likely be a thermal cutout circuit and current monitoring. Either way it needs checking out but it might be one more bit of info you can give the repair shop ?!

ZEN

i didn't mean speaker problems, but if the wires were touching, the amp will immediately go into short circuit protection. worth checking before taking it to repair shop.I'm betting any repair shop would have charged him even if when he went in there was nothing wrong.

i've seen way too many cases of even single strands of speaker wire come loose and cause a short circuit, and simple checking of the wires caused the problem, for me it's first on the lsit of things to check every time, if it doesn't fix it then absolutely, off to a repair shop