I raised the question about the SB fuse because i got sold 2.5A fuses that are SUPPOSED to be SB.
They look like fast blow, but have a "T" for "time lag" on them. Mr electronics wizzkid assured me that they were slo blo due to the T thats on them. Thats how they are made now he says.
Taking his word for it, i put them in my machine and lo and behold, they blow after a short amount of time.
So i source SB fuses that LOOK like SB fuses with the winding inside them, and i havent replaced it since.
Same bloke sold me a 6.2v zener instead of an 8.2 zener - its 1/2hr drive away. Wasnt too happy i can tell you