Hud message:hardaware safety switch

Hi guys
I have the mini pixhawk 3DR, was running ok until I started up a few days ago and the the light is now flashing double yellow , I know is because the system won’t arm due to some issue, when I connect it to mission planner to see the message in the hud it says, hardware safety switch in yellow colour, not only this but all the lines of the hud including some of the messages like battery voltage (was above 11.5) are also yellow.
If I armed the board it will go into flashing blue light and I can arm the motors using the remote control but when I stop the motors and I press the switch to disarm doesn’t make any noise and the motors start making a bip.
I reset the board and format the sd card and installed the firmware again but still the same.
Any ideas??