(Note: If you get a 'file not found' (404) on a link, try again later as article may be in process of being updated. Apple's CDN network has been frustrating at times, including access denied errors.
Some articles have been archived but may still be useful for users of previous OS X versions.) Basics/Apps | Printing | Wi-Fi & Blue Tooth | Audio/Video | i Tunes | Internet/Browsers/Mail | Facetime | Air Play | Air Drop mac OS Security | Backups/Time Machine | Home Sharing | Displays/TV | Apple TV | i Cloud | Migrating Files from a Mac/PC Diagnostics | Troubleshooting | Reinstall OS X | Startup Problems | Ports & Adapters | Apple RAID Cards | Fusion Drives If you're unable to resolve or bind to domains that end in .local (archived) (HT3789 Doc on 'How to disable Bonjour service advertising without disabling DNS' removed by Apple due to changes in OS X Yosemite) If the Ethernet connection on your Mac stopped working recently, follow these steps to restore it (article was removed) It included how to check System Information to find out which version of "Incompatible Kernel Extension Configuration Data" is installed. Mac Basics Guide to Using a scanner in OS X with Image Capture and Preview.
(Link removed as HT201623 article no longer online as of 8/7/2017 check) (The 3 guides below are now listed as 'archived, no longer updated) Apple's Deploy apps in a business environment with i Tunes includes a link to download i Tunes 12.6.5 with built-in App store. The 12.6.4 update allows syncing of i OS 11.3 (and later) devices, which v12.6.3 didn't.) Current i Tunes versions don't support OS X 10.6.x users, but here's i Tunes 11.4 for OS X 10.6.
(FYI to Power PC Mac owners, i Tunes 10.6.3 was last version with PPC support.
(As of August 2017, article is 'archived, no longer updated'.) What to do if Thunderbolt Firmware Update 1.2 keeps reappearing in software update or Thunderbolt ports and Target Display Mode don't work after updating.
(It's the first HDMI device to support the Dolby Vision profile used by Sony, which is different than the Dolby Vision profile used in other TV brands like LG, TCL and Vizio.) tv OS 12.0 added support for Dolby Atmos - see this article.
(original article had info on what's stored in it, when and why you should reset it.) (Intel-based Macs) How to Reset the System Management Controller (SMC) (Includes what to try before resetting SMC, and what problems may be fixed by resetting the SMC.) Resetting the PMU (power management unit) on Power PC Notebooks About 4K, HDR, and Dolby Vision on your Apple TV 4K (Also see footnote about HDR10 and Dolby Vision frame rates.
Some TVs (like 2016 LG OLEDs) don't support 4K/UHD Dolby Vision at 60Hz/50Hz, so 30Hz or 24Hz would be used (or 25Hz for PAL TVs).
(FYI: If you have a 2012 or later Mac mini with File Vault enabled and the display doesn't wake from (safe) sleep, this apple doc says a workaround is to type in your password (despite having no video), which will log you in and wake the display.) "If your third-party display or projector doesn't work in OS X" (as of March 2016 Apple appears to have removed this article (HT203514). Here's the list of supported Mac models (doesn't include 2013 Mac Pro that has Thunderbolt 2): Mac mini (Late 2012): Audio MIDI Setup shows 96(K)Hz output instead of 192(K)Hz (now archived) "The audio controller hardware in Mac mini (Late 2012) supports up to 96KHz audio input and output", correcting a mistake in the original specs that listed 192KHz max.
(As of Jan 17, 2017 revision, the article title and text still has "Hz", which should be "KHz".) Mac mini (Late 2012): External ports and connectors - now routes to Mac mini (Late 2012) - Technical Specs (HT202638 2012 Mac Mini Ports/Connectors article incorrectly listed 192KHz support for Audio.