i upgraded a computer by changing the cabinet(cpu,ram,motherboard.....) and a monitor. the mouse, keyboard and ups are still the same. the weird problem is that even when the computer is off the mouse(its optical) has its light on. even weirder is that even when the ups is switched off the mouse still has its light on and so does the monitor! i double checked connections with the ups several times .........its an old one so im sure about its connections. is there some sort of leakage current . what steps do i take to troubleshoot this problem.