My 15' MacBook Pro (2010) will not boot past a grey screen with Apple logo. There is no startup tone. Progress bar appears and disappears but the progress wheel keeps spinning for
![Security study finds old or improperly updated Macs in limited danger from EFI attack vectors | AppleInsider Security study finds old or improperly updated Macs in limited danger from EFI attack vectors | AppleInsider](https://photos5.appleinsider.com/gallery/23046-28673-boot-top-l.jpg)
Security study finds old or improperly updated Macs in limited danger from EFI attack vectors | AppleInsider
![Fix Macbook Stuck Apple Logo SPINNING WHEEL Not Loading Start Up (Wont Boot Circle Pro Air IMAC 2017 - YouTube Fix Macbook Stuck Apple Logo SPINNING WHEEL Not Loading Start Up (Wont Boot Circle Pro Air IMAC 2017 - YouTube](https://i.ytimg.com/vi/UNpp-qsXk3A/hqdefault.jpg)