MacBook Pro start up

briony85 wrote:

When I turn on, the grey apple icon appears plus black loading bar completes. Then Nothing. What do I do?

If your Mac starts up to an Apple logo or progress bar

https://support.apple.com/en-us/HT207019

briony85 wrote:

Thanks. I spoke to Apple tech support. I had to press Command+R+ Power On. Keeping Command R until Apple icon. Then Reinstall MacOS.

Good computing briony85 !