How much will it cost to have MacBook looked at

Checked would probably be free, but repair is another matter.

Mac Service and Repair - Learn how to get your Mac desktop or Mac notebook fixed and how much it will cost.

Click here --> Mac Repair & Service - Apple Support

Enter the information in the Get Estimate window.

Go to this page to find your nearest Apple Authorized Service Provider (AASP) or Apple Authorized Distributor (AAD) --> Find Locations

How to make a Genius Bar appointment

1. Go to Genius Bar Reservation and Apple Support Options - Apple

2. Go to "Get hardware help".

3. Select your hardware and continue selecting options requiring replacing parts until you see "Bring in for Repair"

4. Sign in with your Apple ID

You can run diagnostics yourself: Use Apple Diagnostics to test your Mac - Apple Support. But if you have a liquid incursion, you're very likely going to need major repairs. Apple doesn't repair; Apple replaces. A logic board for my 2016 MacBook Pro cost $592US three years ago.

Depending on the age of the Mac, cost to repair may exceed the worth of the device.