The blinking signals that the power source has detected an excessive power draw on one of its power rails/output and it's shutting down to protect itself. The first thing you should do is to find out if this is external or internal: disconnect every cable that plugs in the receiver (sources and speakers) and start it on its own, if you get the same result then the fault is internal, if the receiver starts normally then you have a short on one of it speakers - plug them one at a time until the problem returns and replace the failed speaker. If the problem is internal the unit must be opened and the voltage on the rails measured to identify the one that has triggered the warning. Then follow it and test all the components powered by that rail to find out which is the failed component that is drawing too much power and replace it. That procedure requires an extensive experience in electronics repair, you will have to take the receiver to a repair shop.
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The blinking signals that the power source has detected an excessive power draw on one of its power rails/output and it's shutting down to protect itself.
The first thing you should do is to find out if this is external or internal: disconnect every cable that plugs in the receiver (sources and speakers) and start it on its own, if you get the same result then the fault is internal, if the receiver starts normally then you have a short on one of it speakers - plug them one at a time until the problem returns and replace the failed speaker.
If the problem is internal the unit must be opened and the voltage on the rails measured to identify the one that has triggered the warning. Then follow it and test all the components powered by that rail to find out which is the failed component that is drawing too much power and replace it.
That procedure requires an extensive experience in electronics repair, you will have to take the receiver to a repair shop.