The first thing I noticed on the machine was a URL.  It listed  Once I got to this site I sorted through all the options till I came to my machine.  There was a helpful hint on how to overcome the “check tank” error.  Also, supplement this with google searches and my never favorite …searching  I found a great movie that shows exactly how to get past the error.  Basically, one of the little water valves gets clogged and you need to flush it out.  I just used the following link to fix mine.  Get your mouth full of hot water and take a straw to flush out the valve.