Damaged FLIR E6 sensor?

[Flukav]

Dear experts,
I got a free FLIR E6 coming from a fire brigade training centre. For that price, there was of course a trick, radiometric calibration seems lost.
If fired-up next to a working FLIR E5, one may notice blinking images, and a clear issue with lower-scale temperature going down to negative in summer afternoon.
Which part may be damaged or corrupted? Any advice?
Cheers.
Encl: picture and video in link.
https://streamable.com/63nwk3

[Fraser]

An interesting fault.

From the brief video I see relatively normal camera behaviour except the auto span is trying to keep track of a very unstable scene lower temperature boundary. As you likely know, the auto span function looks at the full range of temperatures present in the thermal scene and selects a span that includes that range of temperatures. The instability in the lower temperature setting suggests that the auto span system is seeing very unstable low temperature outputs from the microbolometer ROIC or is interpreting the data as such. This is not a calibration table issue. This is a ROIC output data related problem. It would be worth pointing the camera at a thermally flat surface to reveal any areas of the scene that the microbolometer is reporting as very cold. (Remember to look behind the temperature bar overlay as well as that can hide issues like dead pixels) This might suggest a cluster of damaged pixels that are effectively dead and reporting erroneous minimum temperatures to the auto span system. The instability of the lower temperature boundary certainly suggests pixels that are in distress and barely functioning. If no unusual groups of dead pixels are present, it would suggest that the microbolometer is actually operating OK and so the focus moves to where in the system the fault lies. If you are getting a good thermal image, the microbolometer and ROIC are working in terms of correct capture and processing of radiant energy. The pixel value data will pass from the microbolometer/ROIC ADC to the cameras processor. The ADC may be the source of the corrupted ROIC data so it would be worth looking at that part of the camera. Look for issues with the ADC voltage reference, dry joints and unusual behaviour of the ADC output pins. I suspect you will find the ADC low end data bits are unstable/faulty and causing the issue that you are seeing. If the ADC is integrated into the ROIC, it would be worth checking supply rails and any voltage reference associated with the ADC  function. Sadly a faulty power rail or reference would normally cause errors at all temperatures and not just the lower temperature end of the scale. A failed ADC within an ROIC is sadly a failed complete microbolometer array in terms of repair.

Hope this helps

Fraser

[Flukav]

Some update,
I spent yesterday's night repairing the faulty keypad, 2 keys were non responsive. The responsible was a damaged via on keypad's PCB, with a pale white stain around it. An enameled wire and 2 small welds later, it is back on track, good.
If it could help anyone, I enclosed below the keypad's pinout.
Now, back to the «lower scale» stability issue. If you take a closer look at previous' post picture, you can see a  faulty column, right next to temperature bar. This appears after ~5minutes power-on so one can assume this might due to microbolometer warm-up?
Using «picture in picture» mode, thermal image sides are cropped-out, canceling the erratic behaviour.
Interesting...

[Bud]

Have you tried using in manual scale mode?