I got broken CMIK MK-B60.
After investigation i found blown IC (amplifier) blown was in way that prevent from reading model IC, this is china equipment and no schematic was available. That is probably cheap generic amplifier IC but i decide not to waste time and simple use off shelf amplifier IC in conjunction with DC-DC converter to provide stable power to amplifier IC.
working perfect everything including volume adjustment (it’s just attenuation of input for amplifier that have constant gain) not looking great but cheap!,
