Noisy signal output on GP2Y0D815Z0F proximity sensor

Hi, I’m looking for product support.

I’ve got a setup with six GP2Y0D815Z0F sensors on their pololu carriers.
They are attached to a Rbpi 2 via twisted pair cables, so V supply is 3.3V.
One of the sensors is giving me a noisy output. It’s initially diagnosable looking at the red LED output, which is flickery and looks almost like an analog proximity sense. I checked my solder connections and cleaned the lenses on front. The digital input on the Rbpi shows the same oscillation between high and low, switching to low more often as my hand gets closer to the sensor.
I have checked the connection with the other sensors, which all work fine, and against other connections, which carries the issue with the particular bad sensor.

Further testing:
I was not able to rescue the performance by adding a 10 uF cap to the power supply near the sensor.
I was able to rescue the performance of this sensor by using a highly reflective object surface, or by changing the supply voltage to 5 V.
I was able to replicate the failure mode in a “good” sensor by using a poorly reflective surface.
So, this one sensor is particularly bad at sensing my skin or clothes (the desired target) but fine at sensing glass or aluminum.
This leads me to believe that either the light output is low, or the light input sensitivity is low. I could see both being affected by the supply voltage and reflectivity.

What could be wrong with this one particular proximity sensor? What further test can I do?

I checked the voltage on the proximity transmitter LED and found to be ~1.05V, the same as a few others that I checked.

Hello, Samadam.

I am sorry you are having trouble with one of your Sharp sensors. When you tested the non-working sensor with your RPi 2’s 3.3V supply, was the non-working sensor the only proximity sensor connected to the 3.3V line? (If not, could you try connecting only that sensor to see if the behavior is any different?) Did you keep your setup the same when you checked the other working sensors (i.e. after verifying that the working sensors behave fine, you swapped out the proximity sensor for the non-working sensor, keeping the setup exactly the same, and still got the behavior your described)?

Also, could you post pictures that show the soldering joints on the non-working sensor?