My PSP was working just fine, when one day it suddenly locked up during game play. After a reboot, I got the "Blue Screen of Death." Pressing O, I got it to boot up, however when it got to the wavy line screen, it would just stay there, lines waving, and no icons would ever come up.

Finally, I found that by removing the UMD in from the PSP, it would boot up completely, and seemed to work normally. However, once I placed the UMD into the slot, and rebooted, it did the same wavy line, no icon thing.