SWR SM-400 Issue

[SuperFineLin9]

So The other night I got home From a gig and went a head and just loaded all my stuff to my room as normal.
The next morning I wake up and I hook up my amp to the cap and everything to get some jamming in and as soon as I turn on my amp There was a massive noise from cab (I was scared it was going to blow a speaker)
So I immediately turn my amp off, unplug everything except the power, turn the all the gain, limiter and master volume nobs to zero and turn it on again just for a second.
in that second Preamp Clip and the limiter lights were full on and I noticed a slight electrical hum from the amp.
I havent turned it on yet. I have gotten recommendation from a good friend of mine on who to take it to for repair.

I always carry my own equipment and it wasnt dropped, also I dont think its the tubes.

I was just curious what the issue might be and how much to fix it.

[T-Bird]

Hi.

Even though You don't think it's the tube, that's the first thing I'd replace.

Taking the amp to a tech is also an exellent suggestion.

Regards
Sam

[jastacey]

I had a Studio-225, that did something similar, it turned out to be one of the large caps, decided to blow/pop, was an easy fix and it really didn't cost much ... 15 years ago ... take it in and let a tech fix it

[SuperFineLin9]

Thanks for the advice! Hopefully I can get it done before I hit the road agian (the 20th) but I do have a gig worthy back up just in cas