At boot up circle with a line appears and my MAC doesn’t boot up. HELP!!

What to do when your Mac shows only a gray screen or a Prohibitory sign (no left turn) at Startup:

1) First, use Disk Utility to Repair/First Aid your drive.

Since your Mac is not working normally, you can invoke Recovery Mode by holding Command-R at Startup.

Recovery Mode contains several useful functions, including a special version of Disk Utility that does not need the rest of MacOS to be running to do its job of repairing your disk.

"Regular" Recovery gets the Utilities from special partition on your normal boot drive. If you see a spinning globe, you have invoked (or fallen back to) Internet Recovery, and you see the Globe because it is fetching the Utilities from the Internet. This takes a little longer, so be patient.

About macOS Recovery - Apple Support

Once you get Disk Utility running, this article describes how to repair your disk:

Repair a disk using Disk Utility on Mac - Apple Support

Once Disk Utility reports your drive has been successfully repaired, you can try booting MacOS in the regular way. If that works, you have fixed the problems and you are done.

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If Disk Utility made some repairs, but there are still some problems remaining, you should run it again until your drive comes clean, or Disk Utility reports it cannot be repaired.

If disk Utility suggests you should ERASE your drive, that is a radical step -- this will delete all your files with no possible way of recovering them. Post back here for additional options before you do that.

About the screens you see when your Mac starts up - Apple Support

glennfromjoondalup

To get the best possible advice, you should start a new thread, give it a distinctive title that will attract readers who may know something about YOUR issue, and include what model Mac and what version of MacOS.

some who it has been done and am having trouble with a start up disk dose not exsist?