What are signs that an LSU4.2 is plain shot?

Ive been seeing odd readings, so I took my Tech Edge 3x, checked jumpers in it, made sure it now has LSU4.2 firmware on it, and free-air calibrated it after the recommended 2min of "on" operation..of course in free air.

Will do some more ST logging, to see what I get back now.

 

Behaves differently than a new one...

They're relatively cheap ($50 from Amazon, Bosch 17014) and pretty important for tuning. They should last a long time but are easily damaged by leaving them in place with no power, etc.