Marantz PM66KI amp.

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hotscot

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Joined 2004
Hi everyone

I have the amp. It's missing two large capacitors from the circuit board. Was going to throw it out but wonder if I could repair it.

I do have the schematic and will gladly provide it to anyone who be willing to help me with a little one on one advice on how to source and solder these capacitors.

Regards
Alan
 
T

toman_9

Member
Joined 2006
I also have an PM66 SE and it is broken, after turn-on the fuse is blowing itself up after 5 seconds.

I have the schematics for PM 6010, and looks like it is identical to pm 66. I can send you if you want.

Can anyone help to analyze what faulty on my amp is ?

Thanks.
 
Netlist

Netlist

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Joined 2003
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From the pictures I have from Alan's amp I told him it's beyond repair.
The PCB in the voltage reg. area is too burned in and therefore must have become conductive. It looks like Marantz didn't pay much attention at cooling important transistors.
If toman_9's board is in the same condition I'm afraid I'll have to generate a similar answer.
Is it possible to forward a picture?

/Hugo :)
 
anatech

anatech

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Now that is sad. Is it dark brown or actually burned?

Can I see? Can I, can I, can I ? Please? ;)

Marantz didn't pay much attention at cooling important transistors.
Click to expand...
As you know Hugo, many new engineers don't. Some of the later Revox where really bad in that department. I won't mention Pioneer - oops! Too late! :D

-Chris
 
T

toman_9

Member
Joined 2006
Hi Alan,

I have got your e-mail, however hotmail doesn't want to send the e-mail ..too large... I shall try it tomorrow again.. BTW can you send me the KI schematics ?

Hi Hugo,
The PCB is OK. I do not think it is burned.

Hi Chris,
So what shall I do ?
At the moment the fuse goes off after couple of seconds, I though short circuit andI have already tested one transistor which I identified as faulty. So my next step is to change it (and also may be also its pair).
I know that the transistor was OK when I started the repair, it might have burned meanwhile ... ;-) dunno why..

I checked some resistors with a multimeter, and the values are all ok, same as what in manual says.
So what would be your advise for the next step ?
 
Netlist

Netlist

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I'll forward the manual tomorrow to both toman_9 and Chris.
Meanwhile, it's one of those PCB's that need a firm resoldering.
The two transistors IIRC, Q802 and Q803 are voltage regulators and could be broken. Desoldering the outputs is not a bad idea if they survived till now. If they didn't you will need to take them out anyway.

/Hugo :)
 
anatech

anatech

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Joined 2004
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Hi toman_9,
I would discharge the supply capacitors with a resistor. Then, measure the low value resistors in the output stage. They may be blown and look fine. Keep notes on what you have tested.

I always replace one stage back from the last blown component I find. So far, that would be your driver transistors. One blown output means all in that channel get changed. This for for reliability, and parts are cheaper than time.

So there is work for you to do yet. Take your time and think clearly. That means no beer or other before or while you are working. :drink:

-Chris
 
J

John Tomac

Member
Joined 2004
hotscot said:
Hi everyone

I have the amp. It's missing two large capacitors from the circuit board. Was going to throw it out but wonder if I could repair it.

I do have the schematic and will gladly provide it to anyone who be willing to help me with a little one on one advice on how to source and solder these capacitors.

Regards
Alan
Click to expand...

Hi,

can you send me the schematics too?

Thanks,

Happy new year to everybody here!

Greg
 
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