Hi, my name is Mike and I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. If you look at the drain that connects under the sink and disconnect it there then clear the drain tubing of any blockage there it should clear it.
Is it humming near the bottom?
Have checked the drain under the sink and it is clear. Don't think it is humming.
How about the float inside? Is the float sticking or jammed?
I haven't heard from you. Can I still help?