Solid state amp producing very low ouput

[D,.R]

 

Hello I would require some guidance please.

 

I own a Sunn Beta lead (Solid state sunn amp used by buzz from the melvins, kurt cobain, etc...) which I deeply love.

 

However, one of my band mates was playing around with it and not knowing my amp too well, plugged in my speaker output into the speaker output of the same head - yes dumb mistake.

 

Now the amp does not produce good output. I if plug it through an 8 ohm cab, nothing comes out but if I plug it through a small 4ohm cab, it gets very little volume.

 

My first reaction is to check the fuse but that old thing would not let me. The fuse enclosure is locked it and if I tried to open it up it would break out the fuse from inside. What I would have to do is totally solder out the fuse enclosure and solder another new fuse in a new enclosure to the amp.

 

Does this sound like it is in fact the fuse? I know for tube amps this would probably blow out my output transformer but does that happen to solid states as well?

 

Sorry if my questions are noobish. I am in fact an amateur and know only the basics of amps. I know how not to break them but I am unsure of how to fix them.

 

Thanks in advance!