don't throw that can away!!! most likely it is dirty and that is why it doesn't work. the head sends down a signal to the cash can, the cash can transmits that signal back to the head via three plastic parts. when these get dirty or nicotine or dust that signal is reduced and the head appears to be bad. some people have put them in the dishwasher and it cleaned them, I take it apart and remove the twp plastic optics, and clean the plastic tip on the stacker. takes about 10 minutes after you do the first one. have saved 99% of the alleged bad cans.
these cans are hard to find and getting pricey.
Hope this helps
Jim