WD2500KS-00MJB0 dead, Reverse power connection

Hello marson, sorry to hear that you cannot access your files, hard drive repairs are not supported by WD and usually when a hard drive goes faulty there is not a lot a normal user can do, but there are several community members that can share some advice. You can also check the list of recommended data recovery companies on the WD page. 

Data recovery companies.

http://support.wdc.com/recovery/index.asp?wdc_lang=en

See if the post below helps.

http://community.wd.com/t5/Desktop-Mobile-Drives/Is-the-drive-WD1001FALS-repairable-in-this-case/m-p/302062/highlight/true#M7677