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on 00928 board, both u5630/70 is nostuff. It does not start with no LCD also

ntg, PS get stuck at 5v and no response after that, so i tried ejecting 3.5v on pp5v_s4 and p5vs0_en both at the same time, and i'm able to get 3.5v output on pp5v_s0, which means chip is working. there must be something else causing dropping power. thinking might be 5v sense line.

so this board is back on my table again, and due to the same cause. but this time, nothing i do can get pp5v_s0 back up again. i have pulsing pp5v_s4 and also p5vs0_en but no pp5v_s0 output. i have tried replacing 3 chips and non of them worked. I tried injecting 5v into ppv5v_s0 and board...

so this is now resolved. i did a full reinstall of macOS and upgrade to catalina, now everything works properly. still unsure whats the root cause.

Yes it runs on APFS, so update. i checked the EFI and i forgot that i had password on, so i cleared it. now i get apple logo and boots! great! i get into OS and tested KB and TP, all was fine. BUT i'm still not able to get into diagnostics, recovery or startup manager. could my bios be somehow...

the Bios file is from my test bench unit(which runs fine), exact same model/specs/year. i dump it, clean ME and flashed. i measured U4820/30/50 and all 3 are within good readings. not planning to swap just yet

have tried Clean Bios, no difference. i did use a known good chassis to rule out kb/tp issues but still same. and i know keyboard is ok because capslock lights up when i press it Yes tried preinstalled SSD also it still boot to question mark folder. PRAM reset seems like it does nothing. from...

yeah, i tried without the internal SSD but with external HDD with various macOS installation in it plugged in and none booted

A1502 820-4924 does not boot into anything except ? folder. No diagnostic, no recovery, no external, not even startup manager. Customer said he erase the macbook from icloud and now we can't reinstall macOS anymore. Just so coincidence this is a hardware fault? tested on another chasis to rule...

do you know where is the sensor for cpu core 8 on an a1990 820-01814? or this is normal? but i do get an error saying there is an issue with the SMC during diagnostics...

so where should i check next?

replaced the pin and still the same. measured using a usb C breakout board and diode readings are good.

my bad. a mis-diagnosis from my end. so this board needs the battery to boot properly.

so this 01949 is definitely having issues with 1 of the sensors, i have trouble finding out which cause i do not have another chassis to test with. apple diagnostic took 30 mins to complete and shows SMC error(duhh) but trackpad, kb, fans, webcam all are working. board is pristine, no...

Hello, i have a 820-00045 with initial had charging issues, found short c7131, replaced and device turns on now. Charging still have some issues where only 1 side is able to charge. i replaced u4520 and now it works both side (actually i tested with chip removed and that works so no idea how...

the board has gone from working state to a non-working 20v 450ma now. its a sad sad day cpuvcore is 0.95v no usb activity

yeap. traces are good to u7000(have tried replacing as well) and to R7060. both resister read 2ohms

DCIN_VSENSE = 2.9v DCIN_ISENSE = 0.2v SMC_BMON_ISENSE = 1v PBUS_VSENSE = 2.1v

in terms of resistance they all measure within spec. SMC_BMON_ISENSE = 500mv pulsing DCIN_ISENSE = 0v DCIN_VSENSE = 0v PBUS_VSENSE = 0v all measure when charger is + battery plugged in

okay, was poking around to measure with DMM to measure R5438/39, resister is good. but i noticed R5498 alittle "out of colour" measure resistance all good. tried measuring voltage, i get 0v. i maybe thought its pulsing and DMM not picking up. i used oscope and touch R5498 pin1. suddenly it boots...