- keep the “On” button pressed for not less than 10 seconds (or till the display shows the instrument’s logo).

- Take note that if the instrument’s memory is full the instrument takes more time for the booting procedure while switching on;

- if the instrument shows logo and then turns off: the battery is empty (see in the section “Charge and Battery” the correct way for charging an empty battery).

- If the instrument does not switch on: the battery is empty (see in the section “Charge and Battery” the correct way for charging an empty battery, and the way to solve the charging problems).