MacBook A2681 820-02862

[PITERPENY]

MacBook does not turn on! hangs in recovery but cannot recover, error 21! please help with identifying the fault. consumption 20v/0.086A

[mon2]

It may be the same fault as noted here:

My M1 Mac Can't enter recovery mode even … - Apple Community

[PITERPENY]

thanks mon2. following the forum advice i still get the error.

[mon2]

Test with another cable.

https://discussions.apple.com/thread...28?sortBy=rank

[PITERPENY]

I tried all available cables but the error is always -1, according to the logowik ithis error indicates a problem with the trackpad?

[PITERPENY]

sometimes I get another error 4017 (not on logiWiki)

[PITERPENY]

Any other thoughts on what can be checked?

[mon2]

Check your ssd power rail voltage. If not active, check the resistance to ground of the same power rail.

[PITERPENY]

PP0V88_AWAKE_NAND_VDD=0.8V
PP1V25_AWAKE_NAND_VCCQ=1.25V
PP2V58_AWAKE_NAND_VCC=2.56V
everything seems to be ok with the ssd power supply?! I can turn the macbook on and off with the power button! The macbook plays the power-on music but the caps lock does not light up and I have nothing on the display! Also, when connecting the charger, there is a sound that it is charging and the consumption is 20v/1.5a!

[PITERPENY]

There is no activity on the USB ports! Connecting an external monitor did not help!

[mon2]

No caps lock key toggle means the os has not booted.

You have a chime so that is a good start. Test with an external monitor using a type C hub with a HDMI port. See if you are able to see any graphics through this USB-c dongle.

[PITERPENY]

finally the macbook was restored via dfu without errors and the macbook says something in spanish but there is no picture on either the external or internal display! there is no indication on the dongle! i think it is now on the recovery screen but there is no picture! maybe the problem is in the m2 processor? it does not give a picture? how to check the video outputs on the m2?

[PITERPENY]

Any ideas why there is no display on the screen, no backlight, no keyboard backlight and the caps lock does not work?

[mon2]

No direct knowledge on this model yet but as I understand it - the DFU is like a backdoor to inject firmware onto the board. This operation does not guarantee that the parts onboard will make use of this firmware to boot as normal. That is, if something else is defective then this new firmware not be used to boot. Caps key lock toggle is only if the OS has booted. OS boot will be only if the CPU & SSD are ok as a minimum. Test each and every inductor on the board to confirm the power rails are ok.

[PITERPENY]

What is the system written to when restoring via DFU? Isn't it written to the SSD? If the MacBook asks to select a language, but there is no image, can I exclude the SSD? Or is it better to remove and check the JCID P13 for reading and writing the SSD?

[pc_okay]

Hello,

Did you try to close lid when using external screen?
(You will not Get image in recovery With lis open)
Maybe try to boot/reinstall on external drive too, if this pièce of … Of t2 let you do this!

[PITERPENY]

Hello,

Did you try to close lid when using external screen?
(You will not Get image in recovery With lis open)
Maybe try to boot/reinstall on external drive too, if this pièce of … Of t2 let you do this!

This is a MacBook with an M2 processor (there is no T2 here). Yes, I even tried turning off the display when connecting an external display. ports are not active (only charging) external drive no activity.

[PITERPENY]

finally i localized the problem. ANGLE Sleep Sensor Cable. since no one suggested that i need to check the sleep cable, i didn't even know about its existence 😃. when searching for a display, i saw that some have a cable and checked mine under a microscope and was stunned! the capacitors were rotten. can someone help me identify these four capacitors? or maybe there is some kind of diagram?

[PITERPENY]

I removed the display sleep sensor and the MacBook immediately turned on but with horizontal lines. Will the lines go away when the cable is restored (replaced)? Or is this already a problem with the matrix and the entire display needs to be replaced?