Samsung CLP-510n repair

My Samsung CLP-510n printer has for the most part been a solid unit, except for one issue that seems to be the result of either some poor engineering or bad parts. A couple years ago I started getting a "Replace Waste Toner Tank" message. Now the waste toner tank is just a plastic container where any toner that does not bond to the page during the printing process collects. Yes, it can fill up and yes, printer toner is toxic, but I couldn't see why the whole tank needed to be replaced. So on the first run, I emptied the tank, carefully washed it out and dried it, and put it back in. I was careful to seal and carefully dispose of the waste toner. And all was well with the world

Fast forward a few months...I started to get the message again. The problem this time was there was barely any toner in the tank, but the little optical sensor path was blocked by toner dust on the walls of the tank where the sensor shines through. After lots of cleaning and fighting, I finally got my Dremel tool and cut the tank out where the sensor shines and taped off the opening. Yay! A functioning printer again. Now I just have to check the tank myself every so often to see if it is filling up.

Now we get to about two weeks ago. I started getting the message again...what is going on? I did some more research and ran across this thread on a message board that pointed me to the weak sensor issue. A couple of the posts described where the sensor is, how to get to it, and how to "short" across the receiver to send the printer a constant "OK" signal. I performed this on my printer and documented the process in photos: