my computer on board is not working.

[lvan]

I noticed it earlier but i was lazy to post it.

I dont know why but computer on boeard is tottaly off.
Do you turn this thing on ?I think when I start the car the computer should be on. In the worst case is it pricey to
replace the computer. In that case should I take her to autoelectric. I know that auto electric are rip offs .