Airspeed Dynon Flt Dk 180

[wagflyer]

Had been reading a bit low compared to b-up round dial which seems accurate but now the EFIS shows aprox 30 to 40mph slow. Both round dial and EFIS connected to same pitot line which I've ckd and all look ok. Since both on same pitot and only one appears to work right I assume it is EFIS problem ??
How to confirm and how to fix?? As always, all comments suggestions welcome.

 

[dynonsupport]

If you have at least v5.4.2 (EFIS > SETUP > VRSION) on your EFIS, then you can do a Zero Airspeed Calibration (EFIS > SETUP > SPDCAL). This will reset the 0 airspeed of your system and might correct this issue. If that doesn't do it, then the unit would have to come back to Dynon Avionics for repair. Please call our Tech Support team - 425-402-0433, or email support AT dynonavionics DOT com.

Had been reading a bit low compared to b-up round dial which seems accurate but now the EFIS shows aprox 30 to 40mph slow. Both round dial and EFIS connected to same pitot line which I've ckd and all look ok. Since both on same pitot and only one appears to work right I assume it is EFIS problem ??
How to confirm and how to fix?? As always, all comments suggestions welcome.

 

[wagflyer]

Appreciate your help. Will ck it out.