Recently something happened to my amp, and I'm sure its not the guitar or cable.. There is buzzing on the amp but when I strum theres no sound coming out. Its a 10watt SX Amp.
To tell if it's the guitar or the cable, just plug in your cable first without the guitar and turn on your amp. After that touch the metal tip of the cable with your fingers. If there is an audible hum or static then the problem should lie with your guitar. If there's no difference then either your cable or amp is spoilt.
Try this; w/o plugging anything into the inputs turn up the amps master volume and see/hear if the hiss gets significantly louder. turn the treble knob full to minimum and back again to full is there a difference?
If there is sound difference in hiss then the input jack of the amp may be a problem. If there is no sound then u do have a more serious problem with the amp. Refer to the original seller if warranty is still valid.