Hello everyone. DAC as in the title. After connecting the power supply, the standby mode, the diode lights up, the display is dark. Pressing the power button does not change anything externally. Comes voltage of 1.55V on the controller oscillator, which however disappears after a few seconds. There are no oscillations. Does anyone have experience with servicing these devices? Does anyone have a service manual or a diagram? Thanks in advance for any help