What does the inside back of the fridge do?

Was the back metal or plastic?
If it was plastic then it won't leak any gas....however, if it was metal you may have punctured a pipe if you were very unlucky, more likely your knife will have gone through one of the heat exchange leaves, this won't leak gas.
If you did puncture a pipe then you would have probably heard a hiss as the gas escaped. No noise? then I would give your fridge a try. Don't worry...it won't blow up, at worst it won't chill down, then you can be pretty sure you have punctured a pipe. If it chills, then you have not done any serious damage.

Rob Cavendish
August 2008

Dingaling.next time use you'r hair dryer.anyway,if you've punctured the coils then the gas(toxic)has escaped.if not then running the unit should chill it,no cold?no work.

caine
August 2008