Blown Fuse SloBlo or Fast Acting?

[chunkitup]

I am fixing a solid state guitar amp and the mains fuse is blown. The fuse says .5A250v but no markings to identify slo or fast. I was looking at some tube amps I have worked on and the peavey has fast acting on the primary side of the PT and another amp has sloblo in the same position. Could someone explain to me how to figure out which to use? and which one I should use on the solid state amp?

[olddawg]

In my experience SS amps and SS electronics in general do not use slo fuses. If it required one I think it would be designated. I can't remember seeing a SS amp with an slo fuse.