Audio Systems: Car radio Cassette not working, light fuse, mazda 121

Question
Was trying to replace interior light in my wifes mazda 121 when the bulb emitted a spark and the radio cut out.  Tried to replace blown interior light fuse to no avail.  I even removed radio cassette unit to locate the fuse, again no luck.  Any suggestions?
Regards,
Ian

Answer
Hi Ian!
First (i know it sounds stupid but it is usefull sometimes)check in your car owners manual there should be some info about the fuses two possible locations are the front engine compartement or the left kick panel often under some kind of cover fuse can be named Acc or interior.