Acoustic brand amp blows fuse

[blues harp cat]

This is my 2nd post...
I have an old solid state "Acoustic 134" amp that had been sitting dormant for almost 10 years... when I first turned it on it worked intermittently but was crackling pretty bad...then that's all it would is crackle very loudly even when I didn't turn the knobs...so I sprayed contact cleaner around the knobs... that did not work...then I sprayed the ground switch and fluttered the switch up and down...believe it or not, then IT WORKED...
But after using it for a few weeks I turned it on one day and the fuse blew after about one second...I ordered the exact same fuses which came in today... suffice it to say that I'm glad they came in a package of 10.
Anyway, I installed a new fuse twice...I now have 8 left...
Any ideas on where to start checking and how to do it?
Thank you so very much in advance for any ideas... I'd sure like to save it's life.
It has 4 10" speakers and spring reverb.

[Jazz P Bass]

I would start with checking the output transistors for a gross short.