Answer: - first: this is an electronics group. Your typical toilet (thank god) is devoid of any electronics... imagine a "short" if you will... Second: it's likely that the valve under the toilet has "shed" its rubber washer OR the crud that accumulates in valves which travelled up into the tank-valve and blocked it. That explains the banging and the slow filling. I suggest you do yourself a favor and shut off the main water valve (if possible - yes in a home, no in an appt) replace the valve washer ($0.25) and then replace/repair the tank- valve (replace = ~$12 for a good one). If you've never operated a monkey-wrench or are laughing right now due to its name, I suggest that you call a plumber to avoid serious water damage! -Check the fuse. If it is blown, look for a shorted capacitor or diode. If it still doesn't work you can shit-can the whole thing.