OK reeeeellllyyy stupid question
When the cell readings went from 0.21 to 0.8 in air was the head assembled or was the pod just off and in ambient air?
If in ambient air it rules out any possabuility of 02 leaking into the rig.
When it comes to an electrical issue I get stuck but surley there must be some current interfeering with the calibration? I strugle to beleive all the cells are toast unless there is something on the unit which is frying the cells. What milivolt reading do you get on the cells in air? Is it constant when checked with an Avo meter. Can you conect the avo meter to the cell and then put it in a bag of 02 and see the result.
If its within normal range then there has to be some interferance from the power supply to the hand sets. Some sort of voltage leek
At this point I would have to give up and get someone qualified to look at it
ATB
Mark Chase