Thanks man for the great support…I figured out the problem…I ve just tried with another dc adaptor,and the problem solved.I think the dc adaptor that I used with no problem up to now, has a problem and can’t give enough power to run ur22mkii when 48v switch is on…I used a standart mobile phone 5V adaptor 1800mah and it is ok now…can you please tell me is there any optimum power adapter for ur22mkii? Thanks so much