Hello Fernando, for what you say, your team has problems in the power output stage, the sound does not come out because there is a relay that is not activated as a result of that failure
If you have technical knowledge to review it, I send you the link so you can download the service manual, but go to a specialized technical service
I hope you can solve the problem
Greetings Franco Dosil
Hola Fernando, por lo que cuentas, tu equipo tiene problemas en la etapa de salida de potencia, el sonido no sale porque hay un rele que no esta activado a consecuencia de esa falla
si tienes conocimientos tecnicos como para revisarlo, te envio el link para que puedas descargar el manual de servicio, sino dirigerete a u servicio tecnico especializado
Espero que puedas resolver el problema
Saludos Franco Dosil
http://www.go-gddq.com/upload/2014-10/14100413443414.pdf
SOURCE: marantz PM-74D
Your no doubt finding the speaker safety/turn on surge protect relay NOT engaging a few seconds after turning it on-right? Check the output transistors. These are the big green and black ones screwed to the heatsink. You gain access to them by taking off the bottom cover. There's 4 per channel--2 green and 2 black. You'll probably find one or more of them shorted. If you find replacements, put them in exactly as the originals with new thermal grease/heatsink compound. Unsolder and lift the center pin (collector) on each of the four transistors of the effected channel. Power it up and check across the outside pins of each device for proper bias-about a half a volt or so on each one. If the voltage is much higher, or not there you've got other problems that will require more diagnostic/troubleshooting. Do all the lights on the front panel work-or just the tape monitor indicators? If just the tape monitors light up, check resistors RN83 and RN84 on main board under the speaker connector board-remove the speaker connector board to get at them. These are bad on mine and I've yet to replace them. I believe these to be 920 ohm 1% precision resistors....
SOURCE: marantz PM-74D
Just another follow up, those are 10 ohm resistors not 920 like I'd thought. Marantz did some goofy things with the color bands I guess-brown black black red white-but they're 10 ohms for sure. Odd though because the other two right next to them are ten ohms as well-brown black black gold. Mine was biased a little hot, but I adjusted both channels to idle cooler and it works fine now.....
SOURCE: I have a marantz integrated
please disconnect loudspeaker one by one until the problem is goen -and fix the bad one by change the cabel first and the speaker second if all above does not solve the problem send your amp to service center to repair.
SOURCE: My Marantz PM-45 integrated amplifier
Hi HouseofBlues
The problem you are facing is the speaker protection is turning on to prevent the amplifier from damaging your speakers. It will need some service work done to it to prevent it from happening. I suggest you get it attended to sooner than later, as the problem will be caused by dry solder joints that will need to resoldered, or a semicinductor that is failing. If you are a gun with a soldering iron, you could do this yourself. Check about parts of the amp that runs hot, particularly transistors and resistors in the output stages. resolder all output transistors, and any parts that are mounted to a heatsink. Also focus on areas of the PCB that has discoloured. This is often where the problems occur.
I am more than happy to answer
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Thanks for using FixYa, If you consider the advice I have given you
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you. Cheers.
regards
robotek
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