Mybook world - blue ring - stops working and locks up

Mybookworld-blue ring 1TB has recently started seizing up and going off line similar to many other posts on this forum . It will need to be powered off and then on again to reboot then will work normally for a short time then happens again. It seems that the drive will work properly if I turn an external fan on the unit which is inconvenient. I conclude that it must be overheating even though on board fan is working on start up but possibly not kicking when unit gets hot. Maybe the fan heat sensor is the only problem and nothing wrong with drive itself. Any thoughts. My drive does not seem to have a utility to diagnose the drive.

Not much hope here.  You must backup your data before the drive fails completely.  If it works fine when you use an external fan, definitively it is overheating.