I've got this TRY2100ISD shredder from B&Q (http://reviews.diy.com/2191-en_gb/10787625/reviews.htm). Its been pretty good so far. It jams occasionally. Normally I open it up, clear it, close it and its good to go. This time it won't restart. Any ideas? I've checked the fuse. There is a small black button, not sure what this does but I've pressed it.