D10-A Negative altitude

[danjack50]

In flight, suddenly, the altitude of my D10A started winding down ... it stopped at MINUS 1200 ft, despite the QNH was correct. I quickly checked ground level, but it was far away ...
My D10A has the following accessories: OAT probe, and remote compass (the last one not very useful now that the D10 is connected to a Garmin 695).
Is there hope to restore this by flashing with the last firmware ?
or should the D10 be returned to you for repair (hope not, located in Belgium)
Thanks and best regards,

 

[dynonsupport]

If something had pressurized the static line, you could see such an effect. So first, you should try disconnecting the static line at the back of the unit. It does sound like an issue that is hardware related (the altitude sensor), unfortunately.