Help: Marantz PM-80 ii has died on me

[seoirse2002]

Hi All,
Looking for someone to have a look at my Marantz pm-80..I was using it this morning,then switched it off to go out for a while,came back and switched it on again...the usual click,but no sound,not even through headphones,Ive tried all the obvious,changing speakers,inputs,etc etc to no avail? Any ideas? I can see lights inside still working.
Im useless with this stuff so ideally someone who knows these great amps,if not too far out of London I will take it there as its sooo heavy.
any and all help/suggestions appreciated:)
ps not sure if there is a fuse inside I can check,but dont want to open it up needlessly
George

[synsei]

Is there a fuse holder on the back George? If so you might want to check it. If not the chances are its an internal fuse so you will need to whip its top off. I predict a trip to Maplins in the near future ;)

[seoirse2002]

Thanks Dave
No fuses holders on the back....I guess Ill have to check inside,but before I do maybe someone can tell me if there are fuses inside.
:(

[synsei]

http://www.dutchaudioclassics.nl/img/info/marantz/marantz-pm80mkii/groot/marantz-pm80-mkII-031.jpg

On the board in front of the trafo I'm guessing ;)

[JimC]

If you get the usual 'Click' a few seconds after the Power Button is pressed then the Protection Circuitry thinks there's no problems. Most odd.

Don't think me rude but have you by accident turned the Speakers Off or turned On the 'Tape Monitor'' or similar?
An accidental button press could easily cause what you're experiencing.

These do suffer from 'Dry' Solder Joints around the Output Transistors but this usually causes DC to appear where it shouldn't and you don't get the Click of the Protection Relay connecting the Speakers.

From the Photo kindly added there seems to be a PCB attached to the Front Panel just in front of the Power Transformer, I think I may have had a Regulator fail on this, it was a long time ago so my memory may be playing tricks with me.

Regards,

James.

[seoirse2002]

Thanks for that,but Ive actually tried everything,right down to thinking the speakers had blown and changed them,Ive changed the speaker outputs from a to b,switched the mute on and off,switched class a on and off,and tried all the inputs...zilch...just cant figure it out:(

[UV101]

Can you hear the protection replays clicking? Do they click on and straight off again?

These amps suffer from various issue with dry joints, relay issues, relay control issues and problems with the chip type pre amp.
Its worth getting the lid off and having a look and also looking for dry joints if you can see the bottom of the main PCB. Somethimes there is an inspection plate on the base (cant remember if this is the case with the PM80.

Look for burned resistors on the component side and failed solder joints on the track side.

post some high res pics and I'll take a look. Make sure you unplug from the mains before getting the lid off ;)

[seoirse2002]

Yes I see what I think is an inspection plate on the base that can be unscrewed...my problem is I havent an idea what to look for...dry joint? I knew all about dry joints in my teens,but not the joints we're talking about here and I havent a clue what to look for. As far as I can tell the amp is acting normally when I switch it on...I wait for the click,then turn up the volume...same click happens if I change the speaker outputs from 1 to 2....except now there is no sound...Im totally lost and could just about manage to change a fuse inside if I knew there was one in there,but apart from that,I might as well be looking into a field...there must be someone reasonably close to London (30-50 miles) that can have a look for me. I dont expect it for free,but am reticent about leaving it in somewhere as Ive been stung in the past with the "sharp intake of breath" when I brought other stuff for checking. I do know some people who will look at it for me but they are a long way away and its a monster that I dont want to post.
:(

[UV101]

I could have a look George but it wont be until mid March as I'm packing to move right now. I'm 15 miles southwest of Oxford. If you fancy taking some pics, i'll see it there is anything obvious I can see.

[synsei]

George, have you something to use in the meantime? If not you are welcome to borrow my Mini-T until the PM80 is fixed. I know it is no powerhouse but it does sound nice. Let me know if you do, PM me your addy and I wll post it out to you ;)

[seoirse2002]

I could have a look George but it wont be until mid March as I'm packing to move right now. I'm 15 miles southwest of Oxford. If you fancy taking some pics, i'll see it there is anything obvious I can see.

Hi Ian,
Thanks for the kind offer,I will certainly be in touch if I dont get it sorted before then.Good luck with the move.
George

[seoirse2002]

Hi Dave,
Thanks for the offer,but luckily it isn't my main amp and I also have an Inca Tech claymore and a few others lurking around that I can use,but your kindness is appreciated.:cool: on a different note,Ill be interested to read your thoughts on the Bushmaster you've just acquired,as Ive been thinking about one for a while now.:cool:
George

[synsei]

Simple answer to that George, grab one asap ;)

[seoirse2002]

Thats what I thought....I was just about ready,but now the Marantz prob will have to be sorted first...Im glad it went when it did though as I was just about to list it for sale and buy the bushmaster.At least now Ill know its ok when I do list it,provided I get it sorted soon.I wouldent want to pass a problem to a new owner,although it alway performed flawlessly.Its a great amp.
Im going to open it later and take some pics of the inside so maybe someone will spot something...just hope its a minor thing:(

[seoirse2002]

Update on the Marantz PM-80mk ii....and still looking for someone to look/help me with it not too far out of london....
well I managed to get it open and found 3 fuses inside...took them out and none of them seem blown as the little wire inside isnt broken,so still stuck and no idea why its not working...maybe I should just sell it as it is as Im sure they are quite sought after,then someone can take their time with it.
any ideas?:scratch:

[synsei]

If you can George test the fuses for continuity because although rare, I have experience of internal fuses blowing near the caps therefore they would pass visual inspection ;)

[UV101]

Did you take any hi res pictures George? Might be able to spot something .

[seoirse2002]

Sorry Guys,
Still banging on about the marantz pm80 mk11

Opened it up....took out 2 fuses which were 4amp and close together and took out another single fuse not too far from them which was 3.75 amp...switched on the amp...now no lights.... nothing
went to Maplins,couldent get the 3.75amp fuse but had to buy 10 4 amp ones!
None of the fuses look blown,but Im going to try with 2 new 4amp ones and hope.
Someone told me yesterday that its very unusual for both chanells to go together?
Any thoughts? help?
Still looking for someone that preferably knows this amp to have a look for me please...

[istari_knight]

The preamp on these is an STK module [STK3102] which due to inadequate cooling fails on quite a few units causing silence.... Although its normally preceded by popping or scratching noises coming from the speakers so may not be your problem.

Likewise if regs were at fault I would have expected abnormal noises prior to failure - Are you certain it went from working perfectly to silence just like that ?

[seoirse2002]

well I switched it on...it clicked as usual and was working fine...I then switched it off....about 15 mins later I switched it on again,went to make a cup of tea,came back and turned up the volume.....nothing,so went through all the usual checks and still nothing,I have now changed the fuses,and still nothing...:(

[istari_knight]

Hmm very strange.

Does that model have pre-out / power-in sockets ? If so you could split them to see whats at fault.

[Mr Kipling]

Do you have a recorder of any kind? You could try recording something to see if there is any life when apparently there isn't. Sounds like more dodgey relay activity. The capacitor on the timing circuit might be suspect. Know whatta mean, Matey!

[istari_knight]

Do you have a recorder of any kind? You could try recording something to see if there is any life when apparently there isn't. Sounds like more dodgey relay activity. The capacitor on the timing circuit might be suspect. Know whatta mean, Matey!

Yup, apparently another common fault with these... according to diyaudio threads on faulty PM-80's:

Common visual signs on the PM-80 are burnt 1w resistors near the relays, relay control short circuit [TA7317P] or indeed dried up caps.

Needs a tech IMO.