Hello everybody!
Have in work A1706 820-00239 model. Originally no power, shorted PPBUS_G3H because of corroded C6403, C6404. Some water damage around this components, but nothing major.
After replacing this capacitors the laptop came back to work, I reinstalled MacOS and had no issues until I started to test Type-C ports. Sometimes the laptop shuts off immediately when some action with Type-C ports performed (charger disconnected or USB device inserted/disconnected). I checked Type-C port flexes, they are okay, but I cleaned them anyway. I can't see any signs of liquid...
baglaivlad
Member
Last Activity: 04-20-2025, 05:42 AM
Joined: 09-25-2022
Location: Kyiv
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A1706 820-00239 - Works, but sometimes shuts off when the charger is disconnected
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I am sorry, it was a silly issue. Display connector was torn off the board probably by the previous owner trying to fix water damage. Didn't notice it. Now the connector is replaced and I have a display. -
A1534 2015 820-00045 internal display not detected, but external works
Hi everyone!
Trying to repair A1534 2015 macbook. The keyboard and touchpad was liquid damaged by coke, but the MLB has no signs of corrosion. The laptop successfully turned on, but missed a display flex. Replaced keyboard, touchpad and display flex, but still no image on the internal display (no backlight as well). When connecting to the external display the laptop works just fine (I have an image).
It seems like internal display is not recognized. I tried multiple known-good displays and display flexes, the outcome is the same: no life on the display.
It lead me to believe... -
Yes, try to flash BIOS (make a backup first)Leave a comment:
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Sorry, my mistake, thought A1706 has T2...Leave a comment:
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If you will get 4014/4041 error during DFU restore, itโs probably a bad NAND. If you wonโt get any image (apple logo) during DFU restore, it is a problem on Intel side (bad CPU power, or bad CPU itself).Leave a comment:
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Hi! I couldnโt fix that laptop back then. I was less experienced, but now I would try to flash BIOS IC, like was suggested. Also, I would probably try to enter DFU and try to Revive/Restore the machine (Restore will erase all user data)....Leave a comment:
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Good to know, thank you! Will test purchased LDOs as well.Leave a comment:
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Thank you!
This is how 1.8V output looks like, please see the attachment.
I can borrow some tantalum caps from MacBook boards, if needed....Leave a comment:
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Thank you for additional information. I will buy LD1117AS12TR (for 1.2V, [url]https://eu.mouser.com/datasheet/2/389/ld1117a-1849492.pdf[/url]) and AMS1117-1.5 (for 1.5V, [url]http://www.advanced-monolithic.com/pdf/ds1117.pdf[/url]). Both of them and ASM1117 on my conversion board have the same pinout (1 - Gnd, 2 - VOUT, 3 - VIN).
As far as I understand the datasheet, LD1117AS12TR can be used with ceramic capacitors I have on my board. While about AMS1117-1.5 I am not so sure. It says about tantalum capacitors, not ceramic. Is it ok?
My programmer supplies 3.3V, I checked...Leave a comment:
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Thank you! Will definitely keep you informed! Ordering ASM1117...Leave a comment:
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๐ Yes, TI version has higher voltage requirements. It even does not support 1.8V and meant to be used in 5V to 3V shifters. It confused me too. But I think the logo on my IC is Nexperia (or its Chinese knockoff), which supports 1.8V.
I can order both ASM1117 for 1.5V and 1.2V and try it out. With 1.5V it should work just fine, don't know about 1.2V.
According to my latest question, do you think it is safe to put 1.5V on MX25S6473F inputs? Vcc can be 1.14V-1.6V.Leave a comment:
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Actually, it seems that Nexperia ALVC164245 used in my 3.3 to 1.8 level shifter supports wide voltage range, from 1.5 to 3.6V ([URL]https://assets.nexperia.com/documents/data-sheet/74ALVC164245.pdf[/URL]).
MX25S6473F (IC from MacBook) has Vcc range of 1.14V-1.6V, according to its documentation ([URL]https://www.mxic.com.tw/en-us/products/NOR-Flash/Serial-NOR-Flash/Pages/spec.aspx?p=MX25S6473F&m=Serial%20NOR%20Flash&n=PM2860[/URL]).
How do you think, will it be okay to just convert my level shifter to 1.5V (by replacing ASM1117) and use it with MX25S6473F IC? Yet...Leave a comment:
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Sure. Please see the photos attached. It is based on ALVC164245 IC and buck converter AMS1117 1.8V. I assume AMS1117 can be replaced with the one that outputs 1.2V instead of 1.8V. The question is can I replace ALVC164245 with TXB0108PWR? I should figure it out.
Thank you for your explanation! If any level shifter is available for purchase in US/China, I can buy it and wait some time for delivery. Although, I think with your help I can built my own based on TXB0108PWR....Leave a comment:
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Hi. Thank you. I got a 3.3 to 1.8 level shifter, but not for 1.2V. Unfortunately, can't find it on sale anywhere.
TXB0108PWR IC is available for purchase. Will it fit my needs? Do you have any schematic of 1.2V level shifter to built it? Thank you.Leave a comment:
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Programmer for MX25S6473F (MacBook A2681, U1900, SPI ROM, 1.2V power)
Hi. Please share your knowledge, which programmer can be used to flash firmware for MX25S6473F (SPI ROM, 4x4mm 8-XSON)? This IC can be found in MacBook Air M2 (A2681), U1900. Power and data are 1V25.
[URL]https://www.mxic.com.tw/en-us/products/NOR-Flash/Serial-NOR-Flash/Pages/spec.aspx?p=MX25S6473F&m=Serial%20NOR%20Flash&n=PM2860[/URL]https://Hi. Please share your knowle...ww.mxic.com.tw -
Managed to solve this by replacing U7710, U8110 (ISL95870) and U8500 ICs from A2159 donor board.Leave a comment:
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Any ideas?Leave a comment:
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Sorry, forgot to mention, [B]PPBUS_G3H[/B]โ is present (around 13V, stable).Sorry, forgot to mention, [B]PPBUS_G3H[/B]โ is present (around 13V, stable).Sorry, forgot to mention, [B]PPBUS_G3H[/B]โ is present (around 13V, stable).Leave a comment:
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MacBook Pro A2289 (820-01987-A) No boot/image, but boots to DFU
Hi everyone. Just a reminder I am not a professional repair technician, fixing Apple electronics is my hobby.
Recently got my hands on MacBook Pro A2289 with interesting behavior. Pristine condition, no water damage, no visual issues whatsoever. It has no image, no CapsLock, no life except the fan is spinning. But it is able to boot into DFU and recognized by another MacBook. I tried to revive and restore the laptop, but the process ends when the MacBook usually should show an Apple logo with a progress bar. I assume the main power lines and T2 are working. It seems like the Intel...
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