Works but then display switches of after few minutes
I have an iMac, just over 1 year old, and it's started to switch the screen off, after a few minutes, so here is what happens.
1. Switch on (after being off for a while)
2. Starts and loads
3. working fine then screen goes black but still has backlight
4. all diagnostics LED are on
5. sometime hear noise coming from speakers (clicking-pulsing)
6. shuts of to 1 led but fans still running ( left for 5 mis)
7. short press of power button does nothing
8. holding power button switched off (still 1 led)
9. Machine switches on
10. starts and loads
11. Switches off after 2 mins (fans stop)
12. power button press fans work but 1 led
13. hold power switch fully off
14. press power starts again
15. this just keeps going.
not sure if power supply fault, anyone have any idea?
Is this a good question?