Marantz SM-1151 manual Troubleshooting, Protective Circuits

TROUBLESHOOTING

If you experience trouble with the SM-11S1, make the below checks before thinking the worst. Improper operation can cause the SM-11S1 to behave in a way that makes you think something is wrong with the equipment when actually not. If the trouble cannot be fixed after making the below checks, contact the place of purchase, your nearest Marantz dealer, our customer service center or our repair service center.

¶Power does not turn ON

1.Is the power cable securely plugged into a power outlet?

2.Is the remote power control switch on the rear panel set correctly?

¶Nothing is heard from the speakers

1.Is the SPEAKERS button on the front panel OFF?

2.Is the input set correctly using the BALANCED button or UNBALANCED button on the front panel?

3.Is the gain switching mode in use causing sound to be muted?

4.Are connection cables and speaker cables securely connected?

5.A protective circuit may have tripped causing sound to be muted. If PROTECT is flashing in the display, switch the power off and wait for approximately 1 minute before switching the power on again.

¶Sound from the speakers is not stereo

The MODE switch on the rear panel may be set to BTL. If the switch is set to BTL, switch off the power, change the AMP MODE switch to STEREO, and then switch the unit’s power back on again.

7Protective Circuits

This unit is equipped with protective circuits to protect the amplifier circuits and speaker system against damage. If a protective circuit trips, the sound is instantly muted. In this case, “PROTECT” flashes on the display and the STANDBY indicator also flashes.

¶At Power ON

For about 8 seconds after power is activated, a protective circuit trips and mutes the sound to give amplifier circuits time to stabilize. Once the amplifier circuits stabilize, the protective circuit releases and audio is enabled.

¶In the Event of Over current

A protective circuit trips if current that exceeds the set level is detected, which can happen if excessive signal flow is input to the amplifier, or if the unit is connected to a speaker system of less than 4Ω impedance. A protective circuit can also trip if a speaker cable accidentally shorts. In these cases, “PROTECT” flashes on the display, and the STANDBY indicator flashes red. To release the protective circuits, switch the power OFF, and wait for approximately 1 minute before switching the power back ON again.

¶If Strong Bass Signals Are Input

A protective circuit trips if bass signals of an excessive level are detected.

In these cases, “PROTECT” flashes on the display, and the STANDBY indicator flashes red. To release the protective circuits, switch the power OFF, and wait for approximately 1 minute before switching the power back ON again.

¶If the Amplifier Overheats

A protective circuit trips if the temperature of the main amplifier rises above the set level, which can happen if excessive signal flow is continually input into the amplifier. Temperature can also exceed the trip level of the protective circuits if the vents on the top of the unit are covered, or if the unit is installed on a cramped audio rack. In these cases, “PROTECT” flashes on the display, and the STANDBY indicator flashes red. To release the protective circuit, switch off the power supply and wait for the amplifier to cool to operational temperature before switching the power on again.

¶In the Event of Amplifier Trouble

A protective circuit trips and automatically shuts off the power if an abnormality is detected in the power circuit for whatever reason.The same happens if the main fuse inside the amplifier blows. In these cases, the STANDBY indicator on the display flashes red.

Switch off the power supply, and wait for a few minutes before switching the power on again. If the display does not light and the STANDBY indicator continues to flash after switching the power on again, the unit has a fault.

ENGLISH

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