I have a samsung nm-0802 500G external hard drive that my laptop is not reading even though there is light blinking on the hard drive. how can i get it open in my laptop?

Have you used the power adaptor with the hard drive or are you expecting the drive will take power from the usb port?

Hello,

It sounds like you might have a driver missing for the External drive. I would first try installing the software driver before anything else. Download and install the driver and software from the manufacturer's web site.
Another thing to look at is if whether or not plug and play is disabled in the system Bio's. Course the easiest way to see if that is the case is to plug something else like a pen drive into the USB port and see if it is even working. It may also be that the USB port is not working or is disabled, or better yet your system has only a USB 1.0 port. In which the pen drive may work but it is not enough for the Ext. Hard Drive which requires USB 2.0.
But the remedy is to first try the drivers and software.

Take care.