Can someone help me with a problem with my amp? Really stuck.

[LG18]

I've been using an old marantz amp to power my big KRK monitors for a few years now. The "PM151" is the model.

belonged to my dad, and he bought it in the 80s, so it's fairly old.

it's been fine for years until recently, when the right side Chanel started to crackle, and has slowly deteriorated until now, there's nothing but a very dull crackly at an incredibly low volume, barely resembling the music played at all, rendering that right Chanel useless.

I read somewhere that a leaking capacitor can cause this, but I'm not really sure what to do.

any idea what could cause this?

tHank's allot.

 

[NJB]

I've been using an old marantz amp to power my big KRK monitors for a few years now. The "PM151" is the model.

belonged to my dad, and he bought it in the 80s, so it's fairly old.

it's been fine for years until recently, when the right side Chanel started to crackle, and has slowly deteriorated until now, there's nothing but a very dull crackly at an incredibly low volume, barely resembling the music played at all, rendering that right Chanel useless.

I read somewhere that a leaking capacitor can cause this, but I'm not really sure what to do.

any idea what could cause this?

tHank's allot.

It sounds like you have no gain in that channel or a very bad connection. Provided that you have checked the wires, swapped speakers etc and proved that it is the amplifier, then the first step will be to unplug it and get the cover off. You might spot the problem, especially if a capacitor has gone. However, it sounds as though you are going to need help from either a mate who is good with electronics or a local repair agent to get this fixed. If everything looks ok inside then you have to add fault finding to the mix. At some point you will have to ask yourself how much you love the amplifier, as labour costs will add up quickly and you will quickly exceed the nominal value of it.

 

[LG18]

I've been using an old marantz amp to power my big KRK monitors for a few years now. The "PM151" is the model.

belonged to my dad, and he bought it in the 80s, so it's fairly old.

it's been fine for years until recently, when the right side Chanel started to crackle, and has slowly deteriorated until now, there's nothing but a very dull crackly at an incredibly low volume, barely resembling the music played at all, rendering that right Chanel useless.

I read somewhere that a leaking capacitor can cause this, but I'm not really sure what to do.

any idea what could cause this?

tHank's allot.

It sounds like you have no gain in that channel or a very bad connection. Provided that you have checked the wires, swapped speakers etc and proved that it is the amplifier, then the first step will be to unplug it and get the cover off. You might spot the problem, especially if a capacitor has gone. However, it sounds as though you are going to need help from either a mate who is good with electronics or a local repair agent to get this fixed. If everything looks ok inside then you have to add fault finding to the mix. At some point you will have to ask yourself how much you love the amplifier, as labour costs will add up quickly and you will quickly exceed the nominal value of it.

I checked everything a definitely proved its the amp.

the volume isn't just really low, it's crackly, and barely resembling the music as it should. It did this before but without the low volume, and just progressively got worse with the volume going aswell.

I've had the cover off but I don't really know what I'm looking at or for.

i don't think I know anyone that could fix it and having looked for a repair service I can't find one in my area so of yet, so it might be that I'm stuffed, haha.

thanks for the reply.

 

[Al ears]

Sorry to say it's probably not an economic proposition to repair.

Time for a new one?

 

[LG18]

Yes I fear that's going to be the conclusion.

I'll have to have a look for one.

 

[hg_mike]

Even the PM-351 seems to be valued at only 39 dollars nowadays.

http://www.ebay.com/itm/Marantz-PM-351-Amplifier-/301809573945

So I expect that any repair to your amp, would easily cost more than it would cost to replace like-for-like from ebay.

However if you do have a mate who understands electronics, they might be willing to have a quick look at the insides of the amp, because the problem may be simply a failed capacitor, which is cheap to replace. See this link for examples.