MacBook Air Startup with Exclamation Mark

Hello,

When I start my MacBook Air, I see a white screen with a gray exclamation point in the middle, and I can't do anything.

I took it to a Mac repair shop, and the estimate is 200 euros because they say the hard drive needs to be replaced.

And I have read various things on the internet.

Thank you for giving me your opinion.

Best regards,

Guillaume

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