Drive nothing but a power light

Recently got a WD MyBook Essential 1TB and went through all the initial setup for my Mac, format the drive etc and when I got smartware to install and come up I was told a firmware update was needed so I followed through with that, however noted the first couple times the MyBook would power itself off during the firmware install and I woudl get an improper device removal window but however after second attempt to install firmware update the update did show up on smartware, happy to finally have everything correct I proceeded to collect and unload about 500GB of data from various drives, then when that was all said and done I upgraded my Mac computer to a slightly faster model and hooked MyBook up to it and set it up to do what it was intended for back up and retrieval to newer computer, smatrtware came up and said I needed the firmware update ( I thought this took place on the MyBook ) so I went through the hoops to update my firmware again and once again every time the firmware update is installing and about 80% complete the MyBook powers off give me an ( Improper device  removal) window on my computer, now the MyBook just shows a power light, doesn’t show up on my computer at all not even the VCD, doesn’t show up in disk utility, now what? have I just lost 500Gb of data, yeah I know never put all your eggs in one basket but it was a forced situation and I was planning on redistributing this data for redundant back up