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| MacBook Pro 13 (A1278 820-3115-B) Power button long press to turn on https://vlab.su/viewtopic.php?f=51&t=57683 |
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| bridx [ 23 фев 2017, 20:35 ] | |
| Заголовок сообщения: | MacBook Pro 13 (A1278 820-3115-B) Power button long press to turn on |
Hi, The power button has to be held down for around 10 seconds so it can turn on. A single normal press just lights the white indicator then it goes off. Anyone had a similar issues and anyway of resolving it? Regards |
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| andromedax [ 24 фев 2017, 01:47 ] | |
| Заголовок сообщения: | Re: MacBook Pro 13 (A1278 820-3115-B) Power button long press to turn on |
Check value of R7021 and R7022. You should read 20.02 ohms from pin 27 to pin 28 of U7000. (assuming the problem presents when you are using power from ac adapter) |
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| bridx [ 24 фев 2017, 21:59 ] | |
| Заголовок сообщения: | Re: MacBook Pro 13 (A1278 820-3115-B) Power button long press to turn on |
andromedax писал(а): Check value of R7021 and R7022. You should read 20.02 ohms from pin 27 to pin 28 of U7000. (assuming the problem presents when you are using power from ac adapter) Hi, The values of R7021 (10.4 ohms) and R7022 is (10.5 ohms). Between pin 27 and pin 28 of U7000 is 10.5 ohms. You have to long press with either the battery only, charger only or with both charger and battery connected. U5010 pin 8 does not have any voltage (3.299v) which is present on a similiar working motherboard, it also does not chime but works ok in the OS. |
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| andromedax [ 26 фев 2017, 02:26 ] | |
| Заголовок сообщения: | Re: MacBook Pro 13 (A1278 820-3115-B) Power button long press to turn on |
Цитата: U5010 pin 8 does not have any voltage Measure pin 8 resistance to gnd, without battery or charger connected, if no short or low resistance, replace U5010. |
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