hi Pingu,
It's not a problem at all. It's a perfecty ordinary system "feature". Basically, the Mac goes to "sleep" when left alone for too long. It saves power (good), and also screen life (also good). You can access settings for it from the top Menu bar - its a drop-down menu from that little picture of a battery that may be showing how much battery life is left. Or go to the Apple menu (the apple logo) in the menu bar, and press the muse/trackpad down to show a menu there (which has "About this Mac" at the top). Choose System preferences, Choose Energy Saver, then choose "Show OPtions", then mess with the "Sleep" settings. It's all fairly straightforward, your Mac, once you get used to Apple's human-centred logic, rather than Microsoft's syste,-led pleasure principle. Hope it helps (if I ain't too late).
It's not a problem at all. It's a perfecty ordinary system "feature". Basically, the Mac goes to "sleep" when left alone for too long. It saves power (good), and also screen life (also good). You can access settings for it from the top Menu bar - its a drop-down menu from that little picture of a battery that may be showing how much battery life is left. Or go to the Apple menu (the apple logo) in the menu bar, and press the muse/trackpad down to show a menu there (which has "About this Mac" at the top). Choose System preferences, Choose Energy Saver, then choose "Show OPtions", then mess with the "Sleep" settings. It's all fairly straightforward, your Mac, once you get used to Apple's human-centred logic, rather than Microsoft's syste,-led pleasure principle. Hope it helps (if I ain't too late).

