Broken amp - can anyone help please?? [Archive]

View Full Version : Broken amp - can anyone help please??

Zoidburg

15-02-2011, 14:57

Hi everyone,

I hope this is the correct forum to be posting in and wonder if anyone can help me please? I have a marantz pm 44se amplifier from the mid 90s. I know its nothing special but I had the same amp as a teen (my very first peice of proper "hi-fi" lol) and this brings back a few nice memories.

I bought it cheaply on ebay about 6 months ago, used it without problems for a few months (didnt sound too bad against the pioneer av amp i was using at the time) and then lent it to my dad. Anyway a few weeks later he reported that it had stopped working. No lights commin on and no sound. He replaced the fuse in the plug without success and left it at that.

Im no expert on these things but iv taken the cover off and taken a few shot for you all to see. Does anyone notice anything that looks obvously knackered by any chance?

http://i1085.photobucket.com/albums/j435/zoidburg1975/IMG_0275.jpg

http://i1085.photobucket.com/albums/j435/zoidburg1975/IMG_0274.jpg

There seems to be a fuse that looks like it has darkened / browned in the middles of it so im thinking that maybe this is where the fault could be ?? You can hopefully see it in the pix below..............

http://i1085.photobucket.com/albums/j435/zoidburg1975/IMG_0273.jpg

As I say im no expert on these things and im happy to change the fuse but thats where my ability probably ends lol. So assuming that its the fiuse where would i get a replacement ?

Any advice / help / thoughts / comments would be massively appreciated.

cheers

Ben

tommy6206

15-02-2011, 15:04

Well the fuse in the last pic does look a little black i would try that first

Zoidburg

15-02-2011, 15:07

Well the fuse in the last pic does look a little black i would try that first

My thoughts exactly :)

Any thoughts as to where i could get one though ? What about a maplins maybe ?

John

15-02-2011, 15:27

Maplins or Cricklewood Electronics

biggzy

15-02-2011, 15:49

Agree with above, fuse looks blown.

Adam

The Grand Wazoo

15-02-2011, 15:53

When you find a source for the fuses, don't just buy one!
Fuses often blow for a reason, so just sticking a new one in might just cause it to blow as well.

Stratmangler

15-02-2011, 16:08

Have you got a DMM ?
Sometimes fuses look to be blown and they're not, and vice versa. A simple continuity check would establish whether this is the case or not.

If the fitted fuse is an original it just might have blown due to old age and repeated current surges on power up, but Chris (TGW) is right - it does not make sense to get just one fuse.

Reid Malenfant

15-02-2011, 16:09

When you find a source for the fuses, don't just buy one!
Fuses often blow for a reason, so just sticking a new one in might just cause it to blow as well.
Good point on buying more than one :) I'd have said that fuses only blow for a reason & it generally means something has gone rather wrong :rolleyes:

I notice that there appears to be a plug from the transformer secondary onto the main PCB. I'd suggest that when you get your new fuses you disconnect that plug & just try powering up the transformer on it's own. If the fuse survives it's most likely that the transformer is 100% fine. Power down & leave it alone for a minute then reconnect that plug & try it again. If the fuse blows it's quite probable that either the bridge rectifier is blown or more likely a set of output transistors :doh:

Pity you don't have a multimeter as we could check certain things out prior to possibly doing more damage by trying a new fuse :doh:

Ali Tait

15-02-2011, 17:22

As Mark says, but if you are lucky the fuse could have blown due to age. If you have a close look at the ends of the fuse you should be able to read the rating. Fit a new fuse of the same rating. If it has a "T" on it, that means slow blow, so ask for slow blow fuses when you get your new ones.

biggzy

15-02-2011, 17:32

Wouldn't it be easyer to just take the old fuse with him? thats what i would do as i have not got a clue about fuses lol.

Adam.

Zoidburg

15-02-2011, 17:33

Cheers for the replies dudes, I managed to source a fuse locally but they only had the one, still he let me have it for free which was nice.

So anyhow iv replaced the blown with the new fuse and it powers up and seems to work again, iv had it on for the last hour and all seems fine.

Il keep an eye on it for a while and check out maplins for a couple more fuses just to be on the safe side.

Once again thanks for the replies folks, its always nice to have some back up when your attempting something new.

biggzy

15-02-2011, 17:36

tommy6206

15-02-2011, 17:48

Now I know people say that a fuse will blow for a reason well lets hope the reason yours blew was old age.Happy listening

Ali Tait

15-02-2011, 17:49

Good stuff, hopefully it was just an old fuse.

Zoidburg

15-02-2011, 18:01

Good stuff, hopefully it was just an old fuse.

I'm hoping it was just old age, if blew for another reason is it likely the new one will blow fairly quickly again ?

Iv just checked cricklewood and they seem to have the fuse I need so il get a few more ordered.

Reid Malenfant

15-02-2011, 18:05

I'm hoping it was just old age, if blew for another reason is it likely the new one will blow fairly quickly again ?
If there was a fault i'd have expected it to blow straight away, as has been mentioned i guess it just gave out after a lifetime of current surges at switch on ;)

Lucky eh? :eyebrows:

Zoidburg

15-02-2011, 18:07

If there was a fault i'd have expected it to blow straight away, as has been mentioned i guess it just gave out after a lifetime of current surges at switch on ;)

Lucky eh? :eyebrows:

Let's hope so lol

Alex_UK

15-02-2011, 20:06

Love a story with a happy ending! :)