looks to popped a mosfet or it was fixed in that spot. but u have a short in a mosfet in there. u shouldnt keep powering it up. it will only cause more damage.
unless u just really wanna do it. its not hard just takes time. i wouldn't try it on a class amp unless u really know what your doing cause changing parts is pain to deal with.
yeah but u will need to redo the drive circuit to keep up with the bigger load,and u might have to change the timing of the pwm cause u will need to change the gate resistors.
copper wire. u what what size gauge the wire is? here is some.
http://www.ebay.com/sch/i.html?_nkw=magnet+wire+4&_sacat=0&_odkw=magnet+wire+8&_osacat=0&_from=R40
the two red one are the transformers and the dark one is the inductor. u cant buy them u have to have them rewounded. do u have an amp that has bad transformers?