I own a 28w Epiphone Slingshot25r amp that is a solid state combo with one 12' speaker in it. Recently it has been making crackling sounds when I turn it on. As I play, the crackling will pop in and out. The volume will play normal but then drops really low when the cracking starts. I've tried turning off distortion as well as putting the volume at 1 but it still makes the cracking sound. I've been blasting it a lot at 8 and 9 on the volume level and think I may have broke the speaker in it. I don't trust Guitar Center to check it out; they are the ones I originally bought it from. I don't have the receipt and I bought it over a year ago so the warranty is no good. My question is do you think it's the speaker or could it be something else? If you need further information I'll be happy to supply it.
I tried my dads cable and as soon as I pluged it in the amp started cracking; so I think it may be the speaker or the input on the amp.
Check your grounding connections and power supply cable - try plugging it in another room, check audio cables from your guitar to the amp. Maybe try a different guitar. If you're able to connect the amp to a cabinet or a different speaker go and try (friend's gear, or a shop). If nothing helps, and your not a good with electronics... well you'll probably need to pay for the repair.
My Rig:

+Epiphone AJ100 acoustic
+Fender 60th. Anniversary Stratocaster
+Vox AD30VT
+Vox V847a Wah

look all i wanted was for someone to give me advice on what to do not to slag me off ok

Want advice? Suck yourself off.