Hi.
i have the original DM900UHD. The first time it was started, everything was fine. At the second start, only the red button illuminated and the box did not start. On other forums I also saw some posts about red light and no boot. I tried removing the top cover of the box and pushing my finger on the black cooler on the CPU and launching the box. And he works. The problem is bad CPU soldered on PCB from factory. Perhaps this information will help someone.