Atomization Humidifier not powering up

[dominikkilover]

I decided to use the code and structure for a humidifier powered by arduino which I found online (https://www.youtube.com/watch?v=NbHkHOqMG8Y). But instead of putting a himidity and temp sensor, I put a water level sensor instead. Everything seems to be working fine however, the atomization humidifier is not powering up. What do you think the problem is here? Please help. Thank you! I will also provide the schematic diagram but there were some changes that I did. I plugged the + sensor of the water level sensor on the analog pin 7

[J-M-L]

@dominikkilover

I plugged the + sensor of the water level sensor on the analog pin 7

there is no analog pin 7 on the UNO..

are you using the second power supply or is everything powered by the Arduino ?
take a piece of paper, a pencil and a ruler and draw the circuit as you see it and post a picture of your circuit

[dominikkilover]

Oh, my bad. I mean the digital 7 pin on the arduino UNO. I posted the schematic diagram. Here it is

[jim-p]

None of your solder connections look good
You probably have cold solder joints.
Re-do the soldering
They should be smooth and shiny