Hi everyone, My amplif Marantz PM 7200 has no more bass, treble and balance. The switch class A, AB is dead. The volume works, both speaker works, remote controle works too. Perhaps someone can tell me wath's wrong inside?
An expert who has achieved level 3 by getting 1000 points
2002 made, a 20 year run, not bad for any old AMP.
fuses good?????? yes.
I got confused in the first post gee I can hear it?
but yes the AMP works plays music etc, not told and only tone fails, just that, and we know why.
source direct button is pushed in,OOPS now tone is dead by DESIGN
if still fails we check all DC supplies to tone board 7000
and clean all switch and relay contacts with electronics spray cleaner as we fully cycle each switch.
or pay others huge cash (bread) to do those 2 simple acts.
your call !
users
https://www.manualslib.com/manual/99021/Marantz-Pm7200.html?page=7&term=ohm&selected=3#manual
service
https://www.manualslib.com/manual/837384/Marantz-Pm7200n1b.html
Posted on Aug 15, 2022
Testimonial: "Hi Larry, Thanks for your time. Indeed, in the almost 20 years I've had it, I've never had a problem with it. He's been working with the same Sansui SP 7500 X speakers for all those years. I don't think he stopped liking the speakers overnight. I always used it carefully as I read in the user manual. The problems suddenly appeared only when I need to adjust the tonalities and balance, so it seems that there is a problem somewhere in the tone board. I thought that someone had encountered this problem before, or that it was somehow a common problem, and could send me directly to the fault, without having to measure the whole device. But it looks like that's what I'll have to do. Once again, thank you for your time. Octavian"
we know the button is pushed wrong button ID 21. book 1 above. for sure
in my shop I have scope that send me to the problem every time.
guessing does not work unless cleaning all switches fail.
turn off SOURCE DIRECT
check all inputs for good bad, all sources.
next is DC voltages (supplies are at spec, and not full of HUM )
if still fails make sure output protect relay is not tripped, of sound is there ,this is not it.
the out comes, scope and sig gen. and we find it inch by inch scope probed, L and R path both.
that is it in a nut shell this amp
what means DIRECT,
well that means it is now only and Power AMP, , and that means you have pro grade preamp
as input outside this amp and on said PREAMP or TONE controls or even a omg grahics equalizer.
this is the joy of full component HIFi stereo, if you later want to change something , no need to throw it all away like seen in the case of AVR.
this amp is A pure joy and CLASS A is pure sound, no noise and zero distortion of any kind, CAPS not bad inside. and hum.NOT THERE. if is we fix that first, caps bad go worse even short. bad that.
let me explain put a pure perfect 1KHz sign wave in to the amp and that is what comes out but larger.
CLASS A PUSH PULL BIASED . (AB IS LESS GOOD AND SAVES POWER, LESS HEAT)_
this answer is not the Captain obvious answer (send shop) it is how to fix it easy
and I bet the kids bumped the SOURCE DIRECT
or needs cleaned switches, all child's play cures, no $50 shipping and $300 repairs.
yah think?
page 4
@1 SOURCE DIRECT SWITCH
Press this switch to turn source direct on (depressed) and off
(raised). When source direct is turned on, the audio signal path is
as short and direct as possible in order to enjoy high-quality sources
under the best conditions possible.
I bet this is it, raise the switch now.
there I saved you $400
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An expert who has achieved level 3 by getting 1000 points
Try contact cleaner on dials
Posted on Sep 25, 2022
An expert who has achieved level 3 by getting 1000 points
It is very old and needs to go to a Marantz service centre for service.
Posted on Aug 15, 2022
Testimonial: "Hi Eric, That's exactly what my 10 year old daughter told me, and she's not a Marantz Master. Enyway, thanks for your time. Octavian"
Dont dispose of it, have it repaired. They are very sought after!
just push this
there fixed it. for you, 1 second work.
in the military they teach us ET's to try all modes first or egg hits face or just lost the battle.
see?
and check all inputs too. not just one and to clean the relay and switch contacts. if fails still
send $300 to me now and not Marantz
ask Daughter to pay, advice is free and cheap but not real repairs..
send me Paypal now. (joking here)
this button always kills all tone controls.
by DESIGN. if the button fails or the relays it controls fail and both can be cleaned easy.
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Hi Larry,
I applied everything you told me, plus a few more little tricks of my own, and now I can fully enjoy with my old friend who's coming back to life.
100%.
Not really 100%, but 99,99 for shure.
Greetings from Germany!
Thank you.
Octavian
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