{"id":13093,"date":"2022-05-20T23:06:00","date_gmt":"2022-05-20T15:06:00","guid":{"rendered":"https:\/\/rewa.tech\/macbook-a1502-no-display-issue-repair\/"},"modified":"2024-05-10T14:46:24","modified_gmt":"2024-05-10T06:46:24","slug":"macbook-a1502-no-display-issue-repair","status":"publish","type":"post","link":"https:\/\/rewa.tech\/es\/macbook-a1502-no-display-issue-repair\/","title":{"rendered":"Reparaci\u00f3n del MacBook A1502 sin pantalla"},"content":{"rendered":"<p>MacBook A1502 no display issue repair.<\/p>\n<\/p>\n<p><strong>Modelo:<\/strong> A1502<\/p>\n<p><strong>Junta No:&nbsp;<\/strong>J44 820-3476<\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/MacBook_A1502.jpg\" width=\"1400\" height=\"827\" alt=\"\" title=\"\"><\/p>\n<\/p>\n<h2><strong>Fen\u00f3meno del defecto<\/strong><\/h2>\n<p>No display<\/p>\n<\/p>\n<h2>Proceso de reparaci\u00f3n<\/h2>\n<p>Connect the MacBook and boot it up with the DC power supply, the trigger boot current is 0.15A only which is abnormal.&nbsp;<\/p>\n<p>Detach the motherboard and find the motherboard was water damaged before, and the customer has cleaned it before. The cosmetic of the motherboard looks fine, there&#8217;s no obvious component corrosive or damage.<\/p>\n<p>Then connect the motherboard with the DC power supply machine again, and measure the below voltage values on the relative inductors.<\/p>\n<ul style=\"list-style-type: circle;\">\n<li>=PPBUS_G3H<\/li>\n<li>=PP5V_S4<\/li>\n<li>=PP3V3_S5<\/li>\n<li>=PP1V05_S0<\/li>\n<\/ul>\n<p>The voltage values are normal, but <span style=\"color: #ff6600;\">there&#8217;s no voltage for DDR on the&nbsp;=PPDDR_S and has no power supply for the CPU either.<\/span> Disconnect the DC power supply and measure the diode value, the diode values are all OK.<\/p>\n<\/p>\n<p>Let&#8217;s start with the DDR power supply&nbsp;PPDDR_S3.&nbsp;<\/p>\n<p>As we can see from the schematic, below is the power supply for the DDR<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/DDREG_EN.png\" alt=\"\" title=\"\"><\/p>\n<\/p>\n<p>After measuring, cannot measure the voltage on the Pin 16 (the DDR power supply enable). Disconnect the power and measure the diode value, no short. So we&#8217;ll need to track where is the DDRREG_EN comes from. As we can see from the schematic, it is transferred from&nbsp;PM_SLP_S4_L via R8111.&nbsp;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/R8111.png\" alt=\"R8111\" width=\"1178\" height=\"413\" title=\"\"><\/p>\n<\/p>\n<p>And the R8111 is very close to the DDR power supply chip U7400.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/R8111_on_the_bitmap.png\" alt=\"\" title=\"\"><\/p>\n<\/p>\n<p>Run the voltage value measurement on both sides of R8111, there&#8217;s no voltage.<\/p>\n<\/p>\n<p>Search the signal PM_SLP_S4_L on the schematic again. And check the other test points of&nbsp;&nbsp;PM_SLP_S4_L on the motherboard.&nbsp;&nbsp;<\/p>\n<p>We can measure the high-level voltage on the R8179, but <span style=\"color: #ff6600;\">when measuring the diode value between R8179 and R8111, it&#8217;s shorted.&nbsp;<\/span><\/p>\n<p><span style=\"color: #000000;\">Check the area between the two resistors we can see some corrosive phenomenon, scratch a little bit with the sculpture knife, find it&#8217;s the inner rail broken is caused by corrosion.<\/span><\/p>\n<p><span style=\"color: #000000;\">For the inner rail broken issue, we should jump a wire as the below figure to fix. <\/span><span style=\"color: #000000;\"><\/span><\/p>\n<p><span style=\"color: #000000;\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/Jump_Wire.png\" width=\"1100\" height=\"732\" alt=\"\" title=\"\"><\/span><\/p>\n<p><span style=\"color: #000000;\"><\/span><\/p>\n<p><span style=\"color: #000000;\">Jump wire on the real motherboard as below<\/span><\/p>\n<p><span style=\"color: #000000;\"><img decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/Jump_wire_between_two_resistors.png\" alt=\"\" title=\"\"><\/span><\/p>\n<p><span style=\"color: #000000;\"><\/span><\/p>\n<p><span style=\"color: #000000;\">After jumping the wire the short is gone, and assemble the MacBook to test, display function back to normal.<\/span><\/p>\n<p><span style=\"color: #000000;\"><\/span><\/p>\n<p><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/rewa.tech\/wp-content\/uploads\/2024\/04\/A1502_No_Display.png\" alt=\"A1502 No Display\" width=\"817\" height=\"565\" title=\"\"><\/span><\/p>\n<p><span style=\"color: #000000;\"><\/span><\/p>\n<p><span style=\"color: #000000;\">&gt;&gt;&gt; \u00danete <a href=\"https:\/\/academy.rewa.tech\/\">Academia REWA<\/a> para iluminar tus habilidades de reparaci\u00f3n.<\/span><\/p>","protected":false},"excerpt":{"rendered":"<p>MacBook A1502 no display issue repair. Model: A1502 Board No.:&nbsp;J44 820-3476 Defect Phenomenon No display Repair Process Connect the MacBook and boot it up with the DC power supply, the trigger boot current is 0.15A only which is abnormal.&nbsp; Detach the motherboard and find the motherboard was water damaged before, and the customer has cleaned [&hellip;]<\/p>\n","protected":false},"author":10,"featured_media":13094,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","footnotes":""},"categories":[782],"tags":[],"class_list":["post-13093","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-macbook-repair-case"],"_links":{"self":[{"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/posts\/13093","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/comments?post=13093"}],"version-history":[{"count":0,"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/posts\/13093\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/media\/13094"}],"wp:attachment":[{"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/media?parent=13093"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/categories?post=13093"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rewa.tech\/es\/wp-json\/wp\/v2\/tags?post=13093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}