Aktif Speaker KRK ROKIT5 Audio Trouble

diagnosis

KRK active speaker looks ROKIT5 if we turn the indicator light but no sound came out when we enter the audio input .

KRK speakers ROKIT5 models :

What causes it ? we immediately investigate .

When we turn and we turn we hear sound in speaker , so chances amplifier system is not problematic . So we are no damage estimates tone control section and it is true . Tone control using IC JRC4580 there are some pieces there and once we do we get 1 IC measurements with different voltage at pin number 1 ( voltage -15 volts ) Position IC on the mainboard :

Replacement IC JRC 4580 we do using JRC type 4558 and the results remain the same ( no change ) , there remains the pin 1 voltage -15 volts . We turn off the speakers KRK ROKIT5 and we measure one by one component and the result then we know that 1 Diode 4148 are the cause. We use type diode IN4001 replacement and after replacement process KRK speakers ROKIT5 now is back to normal .