I made this and it's working for almost 2 year,but suddenly a problem raised.

That is turning motor on cause tank full signal and motor stopped after one or 2 seconds.
This happens when water reached on sensor B.

What might be he reason.?

Changed the microcontroller but same result.

http://electronicsforu.com/electron...iy/water-level-controller-cum-motor-protector

 

Did you monitor the μp pins as the sensors are reached?
Also the correct operating voltage on all pins.
Max.

 

Did you monitor the μp pins as the sensors are reached?
Also the correct operating voltage on all pins.
Max.

What are the pins I need to measure ?

Changed all the BC548 but problem still exists.



Yes by disconnecting sensor c cause motor to run continually without stopping after water is full.

If I connect sensor C it cause motor to stop when water reaches sensor B

 

Did the article supply the program file or just a HEX file?
Max.

 

All files are in that link
Program, hex, pcb.