After power, the amplifier has no display, all function keys are invalid, and there is no sound, like when there is no power.
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Push tube breakdown or a small resistance value caused by power tube breakdown, load is too large, the output is caused by shorts
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A sound channel is silent, but the circuit is normal, should check the previous level of each potentiometer, the current sound is large
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Check the power filter capacitor for leakage, as well as other voltage regulator components, the relay does not draw, check whether the output has direct current causing the relay to not draw
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Burning insurance, check whether the power tube breakdown or caused by a short circuit somewhere, sound quality output distortion, should check the bias tube or push, and power tube unilateral damage caused by the replacement of the power tube should be replaced in the whole pair to maintain the good pairing of the two tubes