A copy of my post......
First, I tested all the circuits with each other by using an analog ohmmeter, and noticed no real anomalies in resistance or the smoothness of increases/decreases... what I was looking for was a jump or flat spot or ??
Next, I did the same to a brand new one I have in my stash, pretty much mirrored the older one....... now, how to take it apart.....
I noticed a line, which is really what appears to be a cap sonically welded on, so cut all around that line with my Dremel and metal saw blade. Interesting, there's a cap all right, with a gasket all around it. Notice brass bearing in the "cap" which fits into the actuator shaft in the middle of the blue. Not shown here is the other end of the actuator, there is an o-ring type seal on that end too... this thing is definitely waterproof.
Notice the 4 well soldered contact points to the terminals... debated unsoldering those, but thought, what if I just pry up on the blue thing.....
Well, that was easy! So now we expose the two sets of double contacts, note the four little "fingers" on each contact, which then rub on the "circuits". Up close they look like little back scratchers as the tips are bent such that they are "fingernails" if you will. If you're a genius, you can figure out the circuits and how they are all related... don't hurt your head, LOL.
So next, I took the best closeup I could, and you can see the little 4 finger tracks in each circuit..... these "circuits" are a smooth as glass, I can only presume they are some kind of resistive material like ceramic.
Now, I could not see any anomalies here either, the "tracks" were very minor (normal?) and given there are 4 fingers to give a better chance of picking up a good "signal" and spreading the load, so to speak, I'm not sure why replacing this TPS would have solved a problem....
Sorry no pics, but I got my magnifying glass out and turned the parts at various angles to get the light in various positions..... don't know if you can see it in the pic but the top band has only three "tracks" even though there are four "fingers". I looked at each group of fingers to see if one was "bent" in such a way not to make as good a contact, but found the opposite, in fact, the two outside sets of fingers should have had more force making contact than the middle two sets... not sure why only three traces instead of four, maybe that stuff is harder than we know. The traces are very faint, not as if they are "digging in" or wearing grooves like your old vinyl LP's.
I'll make an assumption that as long as any contact is being made by at least one or two fingers it should be enough. I have to believe there's some overdesign at play here, but who knows. We simply aren't the engineers who would know.
I'm not saying it wasn't a problem, but it doesn't look like it should have been. Let's just say, perhaps more autopsies might be helpful in that regard. I'm going to look at it again tomorrow with fresh eyes and see if there's anything else.... meanwhile, float up some theories if you got any.....
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