820-01949-07 Not starting up

CRC2018

Member
Got an 820-01949-07 in today - problem is it won't start up - stripped it down to just the board and charger and it takes 20V 0.09A current draw. Popped it under the thermal camera and the only thing which is heating slightly is U9080 - nothing visible shorted on the NAND power lines either.

S5 voltages are present but cannot see any S3 or S0 voltages coming up.

Replacing U9080 should fix this issue or is there something else likely going on here? Still not seen many of these style boards!
 

CRC2018

Member
cannot see any SSD voltages coming up - with a new battery connected it's not really made any difference - my USB C meter is showing it hovering up to 0.5a and then back to 0A then looping back up to 0.5A draw again. CPU isn't getting warm and no voltages coming other than S5 ones
 

2informaticos

Administrator
Staff member
I hope you've replaced U9080, before looking for SSD voltages.

Check power on sequence from similar T2 board; 01598 and 01055 available on the forum.
 

CRC2018

Member
Right i've replaced U9080 now and I am getting SSD voltages but the machine is still not powering up. I'll check the power on sequence!
 

CRC2018

Member
Right have looked at the power on sequence and it's getting stuck at PMU_ONOFF_L - it drops from 3.3v to 0v when power button pressed but PP3v3_S5 and PP1v8_S5 do not pulse or appear after this. I have got PP5V_S5 present still though
 

CRC2018

Member
yes that idea did cross my mind but i only have a 2014 13" Macbook Pro. I do not have any newer machines I can use and the hackintosh system I have which does have a thunderbolt 3/type c port on it will not update to 10.15.6 so I can use the apple configurator software!

Is there any way of using the 2014 Pro? i'm guessing not!
 

CRC2018

Member
Well after much messing around I managed to get my hackintosh up to 10.15.7 and ran the apple configurator software. It detected the mac in recovery mode and successfully restored it. All working fine now - is this a common issue after SSD power issues?
 
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