check the two gold pins on the PSP Go camera and the two little holes where the contacts are supplying power to the camera... its likely to be dirty and therefore no power is being supplied to the camera. clean the contacts and the pins and presto! I had the same problem once, tried firmware updates but no go, tried hoovering the usb port like someone suggested but still no go, tried it on a borrowed unit and cam worked! suspected power supply issue, cleaned the contacts and presto!
wingy, November 2009