I have an external hard disk which is connected to my laptop
through the USB port. The hard disk would also need to be connected
to a nearby electricity supply so that it can be accessed by my
computer.
It has been working fine until yesterday, when I tried to power up
the external hard disk by flipping the switch on, my computer can't
seem to detect the hard disk. The hard disk also has lighting
around it and the light is also not on. So now I am not sure what
is the cause of the problem...anyone can help? 
