marantz PM 7200 amp problem. service in mumbai

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toob_noob
Schaut ab und zu mal vorbei

#1 erstellt: 15. Dez 2008, 10:28

yo folks,

need your help here.

have a problem with my marantz amp PM 7200.

amp was ON the other day. Electric iron got plugged in by wifey in the other room. suddenly *phat* sound heard. There was no power. (Everything was running on the inverter which I keep set in UPS mode. So even if there is a voltage fluctuation everything switches to the inverter)

now, the amp is behaving in the following manner :

1. Drastic reduction in volume levels. My normal listening volume position is at 9:00 clock (average between 8:00 clock and 10:00 clock). Now have to take it to 12:00 clock. Even 2:00 clock does not sound uncomfortably loud. previously anything close to 12:00 was absolutely ear-splitting loud. 2:00 clock was never touched before in these many years.
2. Left and Right output is still perfectly okay, in the sense all the musical information is being reproduced from both channels.
3. There is no other static, hissing or other interference noise.
4. Also the traditional click and thump when the amplifier is started is also there.

Based on some testing advise i did the following basic checks.
1. Connected speakers to "Speaker B" outputs. no difference.
2. Connected RCA from CDP to other inputs (Aux1, Aux2). no difference.
3. Connected my Ipod to Aux2. no difference.

the problem remains the same in all cases.

On opening up the amp, could not make out if anything was burnt or damaged. Also no particular burning smell or anything.

So what do you think is the problem ?

I spoke to Samir at Thump, Worli. They deal in Marantz, but will not service a unit not purchased from them. I had bought my unit from Kuala Lumpur when I was based there. Apparently, there are no "authorised Marantz service centres" in India.

However, Samir of Thump opined that the problem might be a blown volume IC.

Can you guys kindly :
a) give your opinions on what might be the problem ?
b) direct me to somebody reliable in Mumbai who I might show it to for inspection.

looking forward to your inputs.

thanks and regards,
toob_noob

Manek
Inventar

#2 erstellt: 15. Dez 2008, 13:32

A friend of mine took his arcam pre/power to lakozy for service before he took it to singapore and they seem to be working fine for the last few months.

Manek

Amp_Nut
Inventar

#3 erstellt: 16. Dez 2008, 10:19

toob_noob,

Just to be sure, please disconnect and reconnect the CD Player to the amplifier interconnect.

If the fasult persists, it probably is a fault in the pre amp section.

Contact Nova Audio: 2600-7700

They do service Hi Fi Equipment.

They are located at Bandra ( off Carter Road ).

All The Best.

toob_noob
Schaut ab und zu mal vorbei

#4 erstellt: 16. Dez 2008, 11:38

manek and amp_nut,

thank you both for your responses.

will contact both and see.

any ideas by the way, on what could have gone wrong ??

one opinion i got was that there could be a problem in the pre-amp section. any other ideas ?

thanks and regards.

Amp_Nut
Inventar

#5 erstellt: 16. Dez 2008, 11:53

While it sopunds bloody trival, could be a loose interconnect. That is why I have suggested ....

While you are at it, also try connecting the CD Player to another input on the PM 7200.

If the same problem persists, it is 99% a fault in the pre-amp section.

toob_noob
Schaut ab und zu mal vorbei

#6 erstellt: 16. Dez 2008, 12:16

hey amp_nut,

i did connect the CDP to aux1 and aux2 and checked. see my first post. result is the same.

thanks and regards.

Manek
Inventar

#7 erstellt: 16. Dez 2008, 12:52

Hi

You said the music quality is the same yet you need to turn the amp up to listen,

Agree with ampnut....

Manek

msb1
Stammgast

#8 erstellt: 16. Dez 2008, 13:45

I had a similar problem with a Classe power amp many years back and it was a blown transistor.