

{"id":20778,"date":"2021-06-28T14:55:24","date_gmt":"2021-06-28T18:55:24","guid":{"rendered":"https:\/\/www.uvm.edu\/it\/kb\/?post_type=ht_kb&#038;p=20778"},"modified":"2025-07-09T13:39:49","modified_gmt":"2025-07-09T17:39:49","slug":"macos-my-computer-wont-start","status":"publish","type":"ht_kb","link":"https:\/\/www.uvm.edu\/it\/kb\/article\/macos-my-computer-wont-start\/","title":{"rendered":"macOS: My Computer Won&#8217;t Start"},"content":{"rendered":"    \t\t<div class=\"hts-messages hts-messages--alert  hts-messages--withtitle  \"   >\r\n    \t\t\t<span class=\"hts-messages__title\">Check your processor version<\/span>    \t\t\t    \t\t\t\t<p>\r\n    \t\t\t\t\tThese troubleshooting steps will ONLY work on a Mac with an Intel based processor. On your Mac, click the Apple icon from the top-left corner of the menu bar, then select the &#8220;About This Mac&#8221; option. If you see Apple M1(or higher) in the &#8220;Chip&#8221; section, it means you&#8217;re using a Mac with an Apple Silicon CPU and the troubleshooting steps below will NOT work for your Mac.    \t\t\t\t<\/p>\r\n    \t\t\t    \t\t\t\r\n    \t\t<\/div><!-- \/.ht-shortcodes-messages -->\r\n    \t\t\n<p>When attempting to boot your Apple computer, you may be shown a flashing folder-shaped icon:<\/p>\n<p><a href=\"https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable.png\" rel=\"lightbox-0\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-20779 size-medium\" src=\"https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable-300x218.png\" alt=\"\" width=\"300\" height=\"218\" srcset=\"https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable-300x218.png 300w, https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable-768x557.png 768w, https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable-50x36.png 50w, https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable-60x44.png 60w, https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable-100x73.png 100w, https:\/\/www.uvm.edu\/it\/kb\/wp-content\/uploads\/2021\/06\/macos-startup-screen-disk-unavailable.png 936w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>If this icon appears, it means that your computer is unable to find an installed operating system.<\/p>\n<p>This can mean that something is wrong with your computer&#8217;s hard drive, your installation of macOS, or your computer&#8217;s power management settings.<\/p>\n<p>Below are several troubleshooting steps to help diagnose and resolve this issue.<\/p>\n    \t\t<div class=\"hts-messages hts-messages--info  hts-messages--withtitle hts-messages--withicon \"   >\r\n    \t\t\t<span class=\"hts-messages__title\">In-Person Support<\/span>    \t\t\t    \t\t\t\t<p>\r\n    \t\t\t\t\tThis is an issue that we are more able to assist with in person rather than remotely. If you&#8217;re on or near campus, bringing the computer to our clinic is likely the fastest solution.    \t\t\t\t<\/p>\r\n    \t\t\t    \t\t\t\r\n    \t\t<\/div><!-- \/.ht-shortcodes-messages -->\r\n    \t\t\n    \t\t<div class=\"hts-toggle  \"  >\r\n    \t\t\t<div class=\"hts-toggle__title\"><h3>Reset PRAM<\/h3><\/div>\r\n    \t\t\t<div class=\"hts-toggle__content\">\r\n    \t\t\t\t<div class=\"hts-toggle__contentwrap\">\r\n    \t\t\t\t\t<\/p>\n<p><div class=\"hts-messages hts-messages--alert  hts-messages--withtitle hts-messages--withicon \"   >\n    \t\t\t<span class=\"hts-messages__title\">Intel Processors Only<\/span>    \t\t\t    \t\t\t\t<\/p>\n<p>\n    \t\t\t\t\tThese instructions do not apply to newer computers with an Apple M1 processor.    \t\t\t\t<\/p>\n<\/p><\/div>\n<p><!-- \/.ht-shortcodes-messages -->\n    \t\t<\/p>\n<ol>\n<li>Shut down your computer.<\/li>\n<li>Turn the computer on and immediately press and hold the following four keys: <strong>Alt + Command + P + R<\/strong>.<\/li>\n<li>Hold for 20 seconds, then release.\u00a0 Your computer may seem to restart.<\/li>\n<\/ol>\n<p>On computers that play a startup sound, you can release the keys after the <strong>second<\/strong> startup sound is played.<\/p>\n<p>On computers that have the Apple T2 Security Chip, you can release the keys after the Apple logo appears and disappears for the second time.<\/p>\n<p><div class=\"hts-messages hts-messages--alert  hts-messages--withtitle hts-messages--withicon \"   >\n    \t\t\t<span class=\"hts-messages__title\">Check your Settings<\/span>    \t\t\t    \t\t\t\t<\/p>\n<p>\n    \t\t\t\t\tAfter succesfully clearing your computer&#8217;s NVRAM, some settings in System Preferences may have changed. Potentially affected settings include sound volume, display resolution, startup disk selection, or time zone.    \t\t\t\t<\/p>\n<\/p><\/div>\n<p><!-- \/.ht-shortcodes-messages -->\n    \t\t<\/p>\n<p>\n    \t\t\t\t<\/div>\r\n    \t\t\t<\/div><!-- \/ht-toggle-content -->\r\n    \t\t<\/div>\r\n    \t\t\n    \t\t<div class=\"hts-toggle  \"  >\r\n    \t\t\t<div class=\"hts-toggle__title\"><h3>Reset SMC<\/h3><\/div>\r\n    \t\t\t<div class=\"hts-toggle__content\">\r\n    \t\t\t\t<div class=\"hts-toggle__contentwrap\">\r\n    \t\t\t\t\t<\/p>\n<p><div class=\"hts-messages hts-messages--alert  hts-messages--withtitle hts-messages--withicon \"   >\n    \t\t\t<span class=\"hts-messages__title\">Intel Processors Only<\/span>    \t\t\t    \t\t\t\t<\/p>\n<p>\n    \t\t\t\t\tThese instructions do not apply to newer computers with an Apple M1 processor.    \t\t\t\t<\/p>\n<\/p><\/div>\n<p><!-- \/.ht-shortcodes-messages -->\n    \t\t<\/p>\n<p>These instructions will vary based on whether your computer is a laptop or desktop, whether it has a T2 security chip installed, and whether the computer&#8217;s battery is easily removed.<\/p>\n<p>See <a href=\"https:\/\/support.apple.com\/en-us\/HT208862\">this page<\/a> to determine whether your computer has a T2 chip installed.<\/p>\n<p><strong>Laptops (T2)<\/strong><\/p>\n<p>Before trying to reset the SMC, try these steps:<\/p>\n<ol>\n<li>Shut down your computer.<\/li>\n<li>Press and hold the power button for 10 seconds, then release.<\/li>\n<li>Wait a few seconds, then press the power button to turn on your Mac.<\/li>\n<\/ol>\n<p>If the issue persists:<\/p>\n<ol>\n<li>Shut down your computer.<\/li>\n<li>On the built-in keyboard, press and hold all of the following keys: <strong>Control + Option (Alt) + Shift<\/strong><\/li>\n<li>Keep holding all three keys for 7 seconds, then press and hold the power button as well.\u00a0 If your mac is on, it will turn off as you hold the keys.<\/li>\n<li>Keep holding all 4 keys for another 7 seconds, then release them.<\/li>\n<li>Wait a few seconds, then press the power button to turn on your Mac.<\/li>\n<\/ol>\n<p><strong>Desktops (T2)<\/strong><\/p>\n<ol>\n<li>Shut down your computer and unplug the power cord.<\/li>\n<li>Wait 15 seconds, then plug the power cord back in.<\/li>\n<li>Wait 5 seconds, then press the power button to turn on your Mac.<\/li>\n<\/ol>\n<p><strong>Laptops (No T2, No Removable Battery)<\/strong><\/p>\n<ol>\n<li>Shut down your computer.<\/li>\n<li>On the built-in keyboard, press and hold all of these keys: <strong>Shift + Control + Option (Alt).<\/strong><\/li>\n<li>While still holding all three keys, press and hold the power button as well.<\/li>\n<li>Keep holding all 4 keys for 10 seconds.<\/li>\n<li>Release all keys, then press the power button to turn on your Mac.<\/li>\n<\/ol>\n<p><strong>Laptops (No T2, Removable Battery)<\/strong><\/p>\n<ol>\n<li>Shut down your computer.<\/li>\n<li>Remove the battery.<\/li>\n<li>Press and hold the power button for 5 seconds.<\/li>\n<li>Reinstall the battery.<\/li>\n<li>Press the power button to turn on your Mac.<\/li>\n<\/ol>\n<p><strong>Desktops (No T2)<\/strong><\/p>\n<ol>\n<li>Shut down your computer, then unplug the power cord.<\/li>\n<li>Wait 15 seconds, then plug the power cord back in.<\/li>\n<li>Wait 5 seconds, then press the power button to turn on your Mac.<\/li>\n<\/ol>\n<p>\n    \t\t\t\t<\/div>\r\n    \t\t\t<\/div><!-- \/ht-toggle-content -->\r\n    \t\t<\/div>\r\n    \t\t\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>When attempting to boot your Apple computer, you may be shown a flashing folder-shaped icon: If this icon appears, it means that your computer is unable to find an installed operating system. This can mean that something is wrong with your computer&#8217;s hard drive, your installation of macOS, or your&#8230;<\/p>\n","protected":false},"author":68,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"ht-kb-category":[272],"ht-kb-tag":[557],"class_list":["post-20778","ht_kb","type-ht_kb","status-publish","format-standard","hentry","ht_kb_category-software-and-licensing","ht_kb_tag-macos"],"_links":{"self":[{"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/ht-kb\/20778","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/ht-kb"}],"about":[{"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/types\/ht_kb"}],"author":[{"embeddable":true,"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/users\/68"}],"replies":[{"embeddable":true,"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/comments?post=20778"}],"version-history":[{"count":14,"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/ht-kb\/20778\/revisions"}],"predecessor-version":[{"id":31562,"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/ht-kb\/20778\/revisions\/31562"}],"wp:attachment":[{"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/media?parent=20778"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/ht-kb-category?post=20778"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/www.uvm.edu\/it\/kb\/wp-json\/wp\/v2\/ht-kb-tag?post=20778"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}