Need Help With "Buzzing" Sub


I have a 7 year old Monitor Audio Silver RSW-12 sub that has been working great until recently.  I moved the sub, carefully, to have the carpets in the room cleaned and now all the sub will do is emit a loud buzzing noise.  It does this with/without the input connected.  I took it apart but dont see anything obvious like loose connections, burnt wires or circuit boards, etc.  Any ideas?  Can this be fixed?  Are replcement amps even available for this unit?  

Thanks,
Chuck
lightngsvt
If it has a fuse, check to see that it is not loose or blown!
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is the woofer blown ?? check with ohm meter.    Is the amp blown, yes you can use any amplifier, you can use an external amp to replace  whatever plate amp the used in there.   
Im pretty much positive the woofer isn't blown, it was working fine before I move the sub.  The fuse is good, I even tried different power cords and outlets.  Can you explain how to test the speaker and amp with ohm meter?  I do have a digital multimeter.