Osmolator Optical Sensor Not Working

[sdheath]

My osmolator recently acting strange, occasionally failing to stop filling until the overflow sensor kicked in. I just unplugged the unit and manually topped off for a few weeks until I had time to investigate. The other day I pulled the optical sensor out and gave it a good vinegar bath and thorough toothbrush scrubbing, thinking that would do the trick. But it still runs the pump whenever power is applied regardless of where the sensor is. Any idea what the problem could be?

I did see the sticky thread above regarding a similar issue, but the image isn't working so I can't try that fix since I can't see the part in question.

 

[rvitko]

The sensor is designed so the pumps should not run at all if it is faulty. Did you change anything with how it is set up (even a new reservoir or something simple is worth looking into)? The date of purchase might also be useful in trying to narrow down the board design. The sticky showed a transformer on the board that could be touching the board creating a short, but this isn't something that just happens down the road, this would be present since the beginning and only affected osmolators made in early 2011. Keep in mind it would be normal for the controller to run the pump for up to 20 seconds after it is first plugged in as the optic sensor takes time to come online and actually send a signal. Also the sensor cannot differentiate between being dry and bubbles so be sure a bubble is not sticking to it.