Original post by: Jaspal Goshal ,
I had this same problem after soldering in a new game cartridge slot to the motherboard. Never done anything like this before so I was fretting when I saw the blinking orange light thinking I might have damaged the motherboard with my soldering iron, or linked two connections somewhere. Turned out after several hours of stress and googling to be a blown fuse in the power board. Just bridged it and now it works. Thank god.