This computer does not appear on a regular basis in the work process sound interruptions. When the sound after withdrawal. Lights flashing on the Panel.NqEservice manual download site
NqEservice manual download site
From blinking lights that point of view, explain in the course of work the machine, the speaker protection circuit protection on a regular basis. Due to "failure" does not appear regularly, doubts there is bad contact in the circuit. To the amplifier input signal source into at any one channel output connection of a speaker repair (I use a cheap speaker 8 ω/50W). Turned the volume down on the 1/4, power, the relay is snap, speaker sound then C12 voltage measurement, beat the circuit board.NqEservice manual download site
NqEservice manual download site
When the beat first, C12 ends of the voltage immediately drops to near 0V, the relay releases, speakers are silent, thus confirming that does have a cold solder joint on a circuit board. In static mode, two-channel power amplifier output voltage measurement, of 0V (normally), when you hit the circuit board, the voltage at the output unchanged. Therefore, the "fault" in the speaker protection circuit and circuit between C9, C10, and C12. With a magnifying glass to observe carefully all solder and copper foil circuit, finally found deficiency of C9 welding on one foot. Again after soldering, "failed" completely ruled out.NqEservice manual download site