SWR 550X- No sound output

So to start off, my gear was gigged with 2 weeks ago and my amp sat for a week after being bounced around a normal amount for a gig. It worked perfect at the gig. The next week at practice, it fired up, fan licked on, but no sound. I tried to bypass the preamp and go through the effects, and that didn't work either.

I brought it home and took of the housing and fired it back up. The preamp tube fires up, and when I put in an instrument cable the preamp clip an limiter light go on. so a signal does go in and the preamp turns on.

I checked if anything looked loose or not attached and don't see anything out of place. So where do I go from here? If anyone has a resource of checklist to go through, or any ideas I'd like to hear them. If possible I'd like to do any work myself. I'm pretty handy but far from an expert.

Thanks in advance!

 

Bump

 

Thanks for the responses. I tried 3 different speaker cables and two different cabs. I checked both active and passive jacks. Yes the speaker switch was on ; )

The preamp and limiter lights flicker when j play and appear to be functioning, as in, they flicker when I dig in like they should.

 

Well it's passive and I checked each non soldered connection and can't find any broken solder joints. Good point on the fuses, one blew on me a year or do ago, but not this time. I'm thinking of selling it as is for parts or a fixer upper if I can't do anything myself.

 

So I'm apparently quite thick. I checked the fuses again and it was in fact the speaker fuse. The housing is ceramic so I had to test with a fresh fuse to know, and it's functioning again. I also noticed that it was a 5amp fuse in there, not an 8amp like it should be. I'm amazed it lasted 2 years. A friend had replaced it and I never noticed what he put in.
Thanks everyone for helping with suggestions.