{"id":13135,"date":"2022-06-10T10:21:00","date_gmt":"2022-06-10T02:21:00","guid":{"rendered":"https:\/\/rewa.tech\/secondhand-iphone-12-pro-max-cannot-boot\/"},"modified":"2025-02-28T12:12:51","modified_gmt":"2025-02-28T04:12:51","slug":"secondhand-iphone-12-pro-max-cannot-boot","status":"publish","type":"post","link":"https:\/\/rewa.tech\/it\/secondhand-iphone-12-pro-max-cannot-boot\/","title":{"rendered":"L'iPhone 12 Pro Max di seconda mano non si avvia"},"content":{"rendered":"<p>Purchasing a secondhand iPhone 12 Pro Max can be a great deal\u2014until you encounter issues like the phone not booting. A black screen with no response, even after charging, can indicate underlying motherboard problems. This guide will walk you through the troubleshooting process and repair steps to get your iPhone working again.<\/p>\n\n\n\n<div class=\"wp-block-media-text is-stacked-on-mobile is-image-fill-element has-blush-light-purple-gradient-background has-background\"><figure class=\"wp-block-media-text__media\"><img fetchpriority=\"high\" decoding=\"async\" width=\"866\" height=\"1024\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/12_Pro_Max_iMage-866x1024.png\" alt=\"iphone 12 pro max\" class=\"wp-image-14821 size-full\" style=\"object-position:50% 10%\" title=\"\" srcset=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/12_Pro_Max_iMage-866x1024.png 866w, https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/12_Pro_Max_iMage-254x300.png 254w, https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/12_Pro_Max_iMage-768x909.png 768w, https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/12_Pro_Max_iMage.png 940w\" sizes=\"(max-width: 866px) 100vw, 866px\" \/><\/figure><div class=\"wp-block-media-text__content\">\n<p><em><strong>Modello:<\/strong> iPhone 12 Pro Max<\/em><\/p>\n\n\n\n<p><em><strong>Annunciato:<\/strong>&nbsp;2020, 13 ottobre<\/em><\/p>\n<\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Feedback del cliente<\/h2>\n\n\n\n<p>A customer purchased an iPhone 12 Pro Max from an online secondhand marketplace. Upon receiving it, they attempted to power it on, but the phone remained unresponsive with a black screen. Charging the device did not resolve the issue.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Risoluzione dei problemi<\/h2>\n\n\n\n<div class=\"wp-block-columns are-vertically-aligned-center is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<ul class=\"wp-block-list\">\n<li><strong>Smontare il telefono<\/strong> \u2013 Open the device to inspect internal components.<\/li>\n\n\n\n<li><strong>Check for Missing Parts or Repairs<\/strong> \u2013 Noticed missing shielding covers and previous repair traces.<\/li>\n\n\n\n<li><strong>Ispezione della scheda madre<\/strong> \u2013 Found evidence of prior repairs.<\/li>\n\n\n\n<li><strong>Test Boot Current with a DC Power Supply<\/strong> \u2013 The boot current remained fixed at 90mA, indicating a CPU issue.<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-gallery has-nested-images columns-2 is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/01__Shielding_plate_is_missing_and_the_screen_has_traces_of_repairing.png\" alt=\"dissemble iphone 12 pro max\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/02__Repaired_before.png\" alt=\"iphone 12 pro max motherboard\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/03__The_boot_current_fixed_at_90mA.png\" alt=\"test iphone 12 pro max using dc power supply\" title=\"\"><\/figure>\n<\/figure>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Possible Causes:<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CPU not working due to poor soldering or damage.<\/li>\n\n\n\n<li>CPU working conditions not met.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Processo di riparazione<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1. Remove the foam and sticker<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Remove the foam around the connectors<\/li>\n\n\n\n<li>Remove the black sticker tape on the bottom side of the motherboard<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/04__remove_the_foam_and_sticker.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Separate the Motherboard Layers<\/h3>\n\n\n\n<div class=\"wp-block-columns are-vertically-aligned-center is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<ul class=\"wp-block-list\">\n<li>Use a heating platform to carefully separate the two motherboard layers.<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/05__Separate_the_motherboard_with_the_heating_platform.png\" alt=\"iphone motherboard repair\" style=\"aspect-ratio:1;object-fit:cover\" title=\"\"><\/figure>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Identify Previous Repairs<\/h3>\n\n\n\n<div class=\"wp-block-columns are-vertically-aligned-center is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<p>Inspect the motherboard and note previous repairs:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The baseband and Wi-Fi chips were previously fixed.<\/li>\n\n\n\n<li>CPU had been repaired before.<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/06__Baseband_and_Wi-Fi_chip_has_been_fixed_before.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/07__CPU_has_been_fixed_before.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n<\/figure>\n<\/div>\n<\/div>\n\n\n\n<p>Based on the boot current fixed at 90mA defect phenomenon, we can try to resolder the CPU to have a try.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 4: Resolder the CPU<\/h3>\n\n\n\n<div class=\"wp-block-columns are-vertically-aligned-center is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<ul class=\"wp-block-list\">\n<li>Remove the CPU and inspect under a microscope.<\/li>\n\n\n\n<li>Found two pads on the CPU chip had been fixed previously.<\/li>\n\n\n\n<li>Scratch out the pad carefully.<\/li>\n\n\n\n<li>Jump wires and form secure connections.<\/li>\n\n\n\n<li>Use a UV mask and cure with a UV lamp.<\/li>\n\n\n\n<li>Reball the CPU and solder it back onto the motherboard.<\/li>\n\n\n\n<li>Place the motherboard into a test fixture.<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-3 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/08__Two_pads_on_the_CPU_chip_have_been_fixed_before.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/09__carefully_scratch_out_the_pad_on_the_CPU.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/10__Jump_wire_and_make_a_circle.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/11__Solder_back_the_CPU.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/12__Test_with_fixture.png\" alt=\"iphone motherboard repair\" title=\"\"><\/figure>\n<\/figure>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Step 5: Assembly Phone Phone<\/h3>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<ul class=\"wp-block-list\">\n<li>Attach the screen and connect the DC power supply to trigger the boot sequence.<\/li>\n\n\n\n<li>The phone powered on successfully, and all functions were verified.<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-4 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/13__Buckle_with_a_screen_and_connect_with_DC_power_supply__trigger_to_boot.png\" alt=\"iPhone 12 Pro Max Cannot Boot\" title=\"\"><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/12_Pro_Max_Cannot_Boot.png\" alt=\"12 Pro Max Cannot Boot\" title=\"\"><\/figure>\n<\/figure>\n<\/div>\n<\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Punti di forza<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A fixed boot current at 90mA often indicates a CPU-related issue, such as poor soldering, missing CPU pads, or CPU damage.<\/li>\n\n\n\n<li>Always inspect secondhand devices thoroughly before purchasing, and review the seller&#8217;s return policy to protect yourself.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Strumenti e parti necessarie<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/shop.rewa.tech\/detail\/ma-ant-motherboard-heating-platform-for-glue-removal.html\">Piattaforma di riscaldamento<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/shop.rewa.tech\/detail\/microscope-auxiliary-objective-lens.html\">Microscopio<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/shop.rewa.tech\/detail\/sugon-3005pm-dc-power-supply.html\">Alimentazione in c.c.<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/shop.rewa.tech\/detail\/uv-curable-solder-mask-oem-new.html\">Maschera UV<\/a> e <a href=\"https:\/\/shop.rewa.tech\/detail\/36w-uv-curing-lamp.html\">UV lamp<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/shop.rewa.tech\/detail\/sugon-t26d-smd-soldering-iron-station.html\">Saldatore<\/a> and reballing tools<\/li>\n\n\n\n<li><a href=\"https:\/\/shop.rewa.tech\/detail\/maant-fx-series-high-precision-jump-wire.html\">Jump wires<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/shop.rewa.tech\/detail\/xzz-motherboard-function-test-fixture-for-iphone-16-series.html\">Test fixture<\/a><\/li>\n<\/ul>\n\n\n\n<p>By following these repair steps, you can successfully restore an unresponsive iPhone 12 Pro Max and avoid common pitfalls when buying secondhand devices.<\/p>","protected":false},"excerpt":{"rendered":"<p>Purchasing a secondhand iPhone 12 Pro Max can be a great deal\u2014until you encounter issues like the phone not booting. A black screen with no response, even after charging, can indicate underlying motherboard problems. This guide will walk you through the troubleshooting process and repair steps to get your iPhone working again. Model: iPhone 12 [&hellip;]<\/p>\n","protected":false},"author":10,"featured_media":13136,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","footnotes":""},"categories":[5,1485,13,158,447],"tags":[],"class_list":["post-13135","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-guide","category-case-study","category-how-to","category-iphone-guide","category-troubleshooting"],"_links":{"self":[{"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/posts\/13135","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/comments?post=13135"}],"version-history":[{"count":0,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/posts\/13135\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/media\/13136"}],"wp:attachment":[{"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/media?parent=13135"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/categories?post=13135"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/tags?post=13135"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}