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Short circuit connecting preamp with amp (RCA)

As there is a short inside the marantz 32 power amp ( dim bulb tester llights full bright) what components should I check first?

I already cheked the output transistors And they are fine. Should i Have to look for some specific resistors or teansistors? maybe some caps?

or should I have to start looking in other place?

Thks
 
petehall347 said:
does the relay click after power up ?
test voltages at speaker terminals .
Click to expand...

With the dim bulb light tester conected ( and full glow bulb ) the relay doesnt clicks . ( using a 120V bulb) . Just to give more info when the amp was working and i used the same DBT with the same 120V , the relya fired up.
 
Just FYI - it works for me - just.

But its the slowest website in the world - took about 10 minutes to download - and then didn't show on the browser screen, although it knew it was a PDF, until I did a "save as..." :)
 
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Hyperion said:
Just FYI - it works for me - just.

But its the slowest website in the world - took about 10 minutes to download - and then didn't show on the browser screen, although it knew it was a PDF, until I did a "save as..." :)
Click to expand...

looks like they are having problems as the site is down right now .. its good to know it works without having to have ubuntu one installed
 
petehall347 said:
check the rectifier .
in case you don't have the manual i have uploaded here http://ubuntuone.com/21QNRtLWfm65pQjz7Lpz1k
tell me if the link works for you .
Click to expand...

Thanks for the links, but I already have the pdf manuals. But I am learning how to read them more or less. I don have to much knowlage in electronics. :no:

Pete one question. when you say to check the rectifier, you mean the bridge rectifier in the Relay board? (CR301) or the Rectifier diode in the bak of the amp board? (CR203).

If you mean CR203 i already checked with the multmeter and it gives lecture in one side and not the other side as a diode supposed to. But as this one is a point to point germanium diode ,I think with the multitester is not sufficient.

Thanks a lot for the help!

Gonzalo
 
If the amp is still set to 120 volt and someone plugged it in with a plug adapter and not a stepdown trafo it could be badly damaged.
Is the amp 240 Volt powered set?
 
Pio1980 said:
If the amp is still set to 120 volt and someone plugged it in with a plug adapter and not a stepdown trafo it could be badly damaged.
Is the amp 240 Volt powered set?
Click to expand...

Thanks for the help.

Yes the amp is 240 Volt powered. I hope the problem is not the Trafo! If that the case how I can test it ?
 
does the power on lights come on ? if so that's a good start .
then check voltages at pins 8 negative rail -41v and 3 positive rail +41v. rectifier relay board .
then check voltages pins 1 and 16 rectifier relay board .these are amplifier output and should be 0v .
 
elgrillo said:
Hi guys , need some help here from the experts please. Im trying to connect a Marantz 3200 preamp and a marantz 32 power amp, but im getting shortcircuit in the main box of the house (Triped circuit in the box).

The preamp alone powers up with out a problem, and the power amp either. But when y connect them with a pair of RCA cables , they generate a tripped circuit breaker at the main panel box.

Anybody knows what could be happening? , what should I check first?

Thanks in advanced and sorry for my poor english!
Click to expand...
I suspect that you have a "ground-fault relay" in your circuit breaker, and
it is that that trips.

The reason is that your poweramp leaks some mains power to the chassis, and when you connect the amps together that currect will go to ground.
The result is that the relay trips.

You have to fix your poweramp. It could be as simple as to remove anti-noice capacitors, it could be the transformer that is leaking.

If you have a "megger" ( high-voltage ohmmeter) you could measure between the chassie and either of the power leads on your poweramp, and
one of them seems to leak. It has to be fixed, it might be dangerous !
 
petehall347 said:
does the power on lights come on ? if so that's a good start .
then check voltages at pins 8 negative rail -41v and 3 positive rail +41v. rectifier relay board .
then check voltages pins 1 and 16 rectifier relay board .these are amplifier output and should be 0v .
Click to expand...

Hi Pete.

Yes the Light light up. :yes:

Ok i will check that (this is always in DC mode? (sorry for my ignorance))

Just to be sure when making the masurments in that points , I have to put the black lead to chassis? or were? (sorry for my ignorance again...)

Thanks

PS : Im going to do this test tomorrow morning cause Im going to Roger Waters Concert tonight here in Paris!!!!!! So happy!!!!
 
elgrillo said:
Hi Pete.

Yes the Light light up. :yes:

Ok i will check that (this is always in DC mode? (sorry for my ignorance))

Just to be sure when making the masurments in that points , I have to put the black lead to chassis? or were? (sorry for my ignorance again...)

Thanks

PS : Im going to do this test tomorrow morning cause Im going to Roger Waters Concert tonight here in Paris!!!!!! So happy!!!!
Click to expand...

Another question...

When making this test in the rails. Do i have to do it directly to the ac wall outlet? or throw the dim light tester? Im afraid that if I connect it directly to the wall outlet it makes more damage...


Thanks!
 
keep using dim bulb until its fixed ..
voltages DC reference chassis ground . or any pin 4 5 6 7 .. rectifier relay board ..
 
elgrillo said:
Hi, today I found something strange in the preamp. I put the Multimeter in conectivity mode and put the read lead in the iner RCA , and the black lead in the outer RCA , and i got a a beep . is that normal?

Then i checked the others rca's and found that in the Tune, phono 1 , and phono 2, the same beep as in the preamp output.

In Aux, tap 1 and tape 2 ( in and out ) no beep at all?

is that right?
Click to expand...

I don't know why no one has mentioned that you don't use continuity (a resistance mode) to check for DC offset or other fault. You need to use the DC volts scale. In continuity mode, all the beep is telling you is there is a circuit resistance below 200-300 ohms.
 
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Glen B said:
I don't know why no one has mentioned that you don't use continuity (a resistance mode) to check for DC offset or other fault. You need to use the DC volts scale. In continuity mode, all the beep is telling you is there is a circuit resistance below 200-300 ohms.
Click to expand...

read post 6 onwards ..
 
petehall347 said:
keep using dim bulb until its fixed ..
voltages DC reference chassis ground . or any pin 4 5 6 7 .. rectifier relay board ..
Click to expand...

Hi Peter,

So this morning i was able to make the tests.

Using 120W bulb tester

Pin 3: (DC set in 1000) between 9-10V
Pin 8: (DC set in 1000) -10V

Pin 1: (DC set in 20) .07V
Pin 16: (DC set in 20) between 0 -.08V (fluctuation)

This is ok for the trafo?
 
elgrillo said:
Hi Peter,

So this morning i was able to make the tests.

Using 120W bulb tester

Pin 3: (DC set in 1000) between 9-10V
Pin 8: (DC set in 1000) -10V

Pin 1: (DC set in 20) .07V
Pin 16: (DC set in 20) between 0 -.08V (fluctuation)

This is ok for the trafo?
Click to expand...

Im going to check the rectifier bridge now, as Peter told me.

The readings in the trafo are all right? or do I have problems with it?

Thx!
 
petehall347 said:
check the rectifier .
in case you don't have the manual i have uploaded here http://ubuntuone.com/21QNRtLWfm65pQjz7Lpz1k
tell me if the link works for you .
Click to expand...

I checked the bridge rectifier with the multimeter in diode mode.

Red in negative and black in either AC : .691 and .702
Black in positive and red in either AC : .697 and .706
Black in positive and red in negative : 1.689

All the other alternatives = no readings.

The rectifier was out of the board in all readings.
 
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