So I'm writing for a friend who owns a Line 6 Spider 212 (100 watts).

The story goes:  He was playing guitar in his basement and was goofing around and apparently caught his guitar on an exposed (electrical) wire.  In the process of electrocuting himself, he also did some damage to the amp. 

Now the amp has the 60 cycle hum (or very equivalent sound) no matter what is plugged into it.

I would like to fix this myself, if possible, and save my friend some money.

Thanks