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Advanced multichannel power amplifier M-770

The sistem when is on blow a fuse, but when i remove a relay the sistem can be on and the fan works, but the sound is in and out.

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Re: advanced multichannel power amplifier M-770

The relay sounds as if it is controlling the "mute" circuitry. If you power down the relay there is no power to the speakers. When you pull it out it is the same thing as putting it in the open position.

Just for giggles, leave relay in, before turning on, unplug your speakers, volume all the way down. Now "mute" the device. first plug the speakers in, if fuse is not blown, try adding a little volume.

With the speakers and volumke down, there is little or no current dfrawn from the amplifier section. If the device blows a fuse this time, I suspect the amplifier control voltage circuitry is bad.

If blown when attaching the speakers, susoect the amplifier circuitry.

Of dourse this does not take into account a good ol' short on the board. This would just mean that the short is AFTER the relay or there is a possibility that the relay control circuit is causing this.

There are multitude of diagnostics for a pre-amp/amp combo and either way, if your not a technician, it needs to be taken some place for proper diagnostics.

Posted on Dec 04, 2007

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