iMac hangs on start-up?

[MiniD3]

Hi guys,
Just started happening in the last week,
When I switch on, the little black line runs from left to right and hangs in the centre and will go no further
I then re-boot and the system starts OK
The system is,
750SSD

.......Gary

 

[JohnDS]

Boot into recovery mode by holding down command-R and run Repair Disk from Disk Utility First Aid.

 

[MiniD3]

Boot into recovery mode by holding down command-R and run Repair Disk from Disk Utility First Aid.

Tks John,
For the first time this week, sure enough, it booted OK this morning,
When I do the ⌘R option, ist the repair automatic?
And is that all I have to do?
Sorry for the other questions, this 70 year old is a bit behind the technology
.......Gary

 

[JohnDS]

1. Reboot the Mac and hold down Command+R to boot into Recovery,
2. At the Mac OS X Utilities screen, select “Disk Utility”
3. Select the boot volume or partition from the left menu and click on the “Repair” tab

Details with pictures here: http://osxdaily.com/2012/02/08/repair-boot-disk-mac-os-x-disk-utilit/

 

[MiniD3]

1. Reboot the Mac and hold down Command+R to boot into Recovery,
2. At the Mac OS X Utilities screen, select “Disk Utility”
3. Select the boot volume or partition from the left menu and click on the “Repair” tab

Details with pictures here: http://osxdaily.com/2012/02/08/repair-boot-disk-mac-os-x-disk-utilit/

Much appreciated John
.......Gary