Halcro DM10 repair

Does anyone knows how to repair the Halcro DM10 preamp in U.S.? My Halcro DM10 recently has no sound coming out of left channel when in the middle of listening session to the phono (it is not tuntable since I swapped the interconnect cable), line section appears to have no issue. The only way to solve this issue is to power cycle the unit, then it sounds just fine for another couple hours before left channel stops working again. Since there is no degradation in the sound quality and power cycle can solve this issue. This tells me that the audio circuitry in the analog section appears to be fine. The problem appears to be in the microprocessor control section, possibly the relay. I am trying to open it up but I do not know how to open it since it has no visible screws. I am wondering does anyone have the experience to open the Halcro preamp/amp? or does anyone knows how to get the schematic? I heard Halcro is out of business and I also do not wish to sent it to Australia if it is a simple fix.