{"id":12973,"date":"2021-11-04T12:00:00","date_gmt":"2021-11-04T04:00:00","guid":{"rendered":"https:\/\/rewa.tech\/a1706-2016-version-can-not-be-turned-on\/"},"modified":"2024-05-10T15:25:01","modified_gmt":"2024-05-10T07:25:01","slug":"a1706-2016-version-can-not-be-turned-on","status":"publish","type":"post","link":"https:\/\/rewa.tech\/it\/a1706-2016-version-can-not-be-turned-on\/","title":{"rendered":"A1706 La versione 2016 non pu\u00f2 essere attivata"},"content":{"rendered":"

Scheda madre n.<\/span><\/strong>\uff1a<\/span>820-00239-08<\/o_p><\/span><\/p>\n

Fenomeno di malfunzionamento:<\/strong> <\/o_p><\/span><\/p>\n

Macbook A1706 2016 Version can not Be Turned On with abnormal standby status.<\/o_p><\/span><\/p>\n

Possibili motivi:<\/strong><\/o_p><\/span><\/p>\n

The converting process of 5V to 20V was abnormal;<\/o_p><\/span><\/p>\n

The standby circuit or the chips related with standby circuit was abnormal;<\/o_p><\/span><\/p>\n

<\/span><\/p>\n

Risoluzione dei problemi:<\/strong><\/o_p><\/span><\/p>\n

We connected with power and check the current when the voltage converting from 5V to 20V, the current was normal, it means the PPBUS_G3H was generated. But when we press the power button, the MacBook couldn’t be turned on, it means the problem was from the standby circuit or related chips.<\/o_p><\/span><\/p>\n

<\/span><\/p>\n

We removed the back cover and disconnected the battery, connected with power cable to check the standby current.<\/o_p><\/span><\/p>\n

\"A1706<\/p>\n

After that, we disconnected the power and take out the motherboard, check it. There wasn’t any water damaged area or other obvious damage. Then we continued to check the diode value of the standby lines.<\/o_p><\/span><\/p>\n

VCCRTC of PP3V0_G3H was 405, normal; <\/o_p><\/span><\/p>\n

L7660 on PP3V3_S5 was 399, normal;<\/o_p><\/span><\/p>\n

VCCPRIM_3P3 of PP3V3_SUS was 310, normal;<\/o_p><\/span><\/p>\n

L8020 on PP1V8_SUS was 320, normal;<\/o_p><\/span><\/p>\n

L8050 on PPVCCPRIMCORE_SUS_PCH was 251, normal;<\/o_p><\/span><\/p>\n

L8000 on PP1V0_SUS was 227, normal;<\/o_p><\/span><\/p>\n

According to the result, all the diode values were normal, then we continued to check the voltage, <\/o_p><\/span><\/p>\n

The voltage of VCCRTC PP3V0_G3H was 3.3V, normal;<\/o_p><\/span><\/p>\n

 <\/span>The voltage of PP3V3_S5 on L7660 was 1.9V, abnormal, the normal value should be around 3.3V; <\/o_p><\/span><\/p>\n

Then we located the inductor L7660 and related circuit as follows.<\/o_p><\/span><\/p>\n

\"\"<\/p>\n

L7660 was controlled by U7650, the voltage was 1.9V, it was lower than normal value. <\/o_p><\/span><\/p>\n<\/p>\n

There are 3 main reasons that can cause the output voltage lower.<\/o_p><\/span><\/p>\n

The feedback circuit was abnormal; <\/o_p><\/span><\/p>\n

The chip was broken;<\/o_p><\/span><\/p>\n

The circuit between the chip and test point was abnormal;<\/o_p><\/span><\/p>\n

We connected with power to check the feedback rail as the following picture shows.<\/o_p><\/span><\/p>\n

\"fix<\/p>\n

Pin 16 VFB2 of U7650 was the feedback signal receiving pin. The voltage PP3V3_S5 of this rail was divided by two resistors, R7698 and R7699. We checked the voltage on pin 16 of U7650, the value was 1.7V, abnormal, normal value should be around 0.99V.<\/span><\/p>\n

We disconnected the power to check the diode value on pin 2 of R7698 and R7698, the value on R7698 was 510, the connection bettwen R7698 and the chip U7650 was good.<\/o_p><\/span><\/p>\n

\"repair<\/p>\n

Then we checked the resistance of R7698 and R7699, the value of R7698 was 23KΩ, it was normal, the value on R7699 was 25KΩ, which was abnormal, normal value should be around 10KΩ.<\/o_p><\/span><\/p>\n

We replaced another resistor R7699, and check the resistance, the value was 10KΩ. Then we connected with power and checked the voltage on pin 16 of U7650, the value was back to normal 1V after we checked. We continued to check the voltage PP3V3_S5, it was normal value 3.3V. We assembled all parts and tested the MacBook, the standby current was back to normal and all functions worked normally. The problem was resolved.  <\/span><\/o_p><\/span><\/p>\n

\"\"<\/p>\n

Sintesi:<\/strong><\/o_p><\/span><\/p>\n

The resistor on the rail of feedback signal was broken, caused the feedback voltage abnormal, then the output voltage PP3V3_S5 was lower, we replaced the resistor R7699, the problem was resolved.<\/o_p><\/span><\/p>\n

<\/span><\/p>\n

Go to REWA Academy to Learn More>><\/span><\/a><\/strong><\/p>","protected":false},"excerpt":{"rendered":"

Motherboard No.\uff1a820-00239-08 Malfunction Phenomenon: Macbook A1706 2016 Version can not Be Turned On with abnormal standby status. Possible Reasons: The converting process of 5V to 20V was abnormal; The standby circuit or the chips related with standby circuit was abnormal; Troubleshooting: We connected with power and check the current when the voltage converting from 5V […]<\/p>\n","protected":false},"author":10,"featured_media":12974,"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-12973","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-macbook-repair-case"],"_links":{"self":[{"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/posts\/12973","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=12973"}],"version-history":[{"count":0,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/posts\/12973\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/media\/12974"}],"wp:attachment":[{"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/media?parent=12973"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/categories?post=12973"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rewa.tech\/it\/wp-json\/wp\/v2\/tags?post=12973"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}