Old 2009 iMac won't start up
I have a old (2009) iMac that won't boot. When I turn it on, it brings up the apple logo and the progress bar and progresses to the end of the progress bar and then the screen goes black. I have tried power cycling and I have unplugged all accessories. I have tried Command-R. Nothing works. Any ideas ?
iMac 27″, macOS 10.13