I am looking at an A2337 and found this for the order of power rails and what they do. Can this be confirmed before I dive into hunting down power rails that do not exist or are not neccisary?[LIST][*][B]PPBUS_G3H (12.6V-12.8V)[/B][LIST][*]This is the main power rail that supplies power to the entire system. Check this rail first, as it must be present for other power rails to work.[/LIST][*][B]PP3V42_G3H (3.42V)[/B][LIST][*]This power rail is derived from PPBUS_G3H and is used to power the SMC (System Management Controller) and other essential circuits. It should be present if PPBUS_G3H is working...

Hey everyone!

I have a MacBook Pro A1989 with a 820-00850-A board that recently stopped working. I used it overnight to charge my phone, in the morning it didn't turn on, I assumed flat battery but now won't charge and doesn't start at all.

I have fully dissassembled it, when disconnected the battery reads at 0.012V. Even with the battery disconnected the laptop doesn't boot.

The diode voltages around all 4 CD3215's seem fine.

For all CD3215 (UB300, UB400, U3100 and U3200) I read just above 5V on PP20V_USBC_TA_VBUS, 3.3V on PP3V3UPC_TA_LDO, 1.8V...

Hey guys, just troubleshooting a MacBook Pro A2289 with the 820-01987 logic board.

No fan spin, no booting, device not getting detected by the Apple Configurator.

Did a few basic things, the board gets to 20V USB supply according to my USB tester, F7000 fuse seem to be ok and not blown.

Board draws about 0.5A for about 10 seconds, after that it goes down to 0V. Found an n channel FET (Q4830) in the backlight supply(?) that could to be blown (pictures below), not quite sure about that, but t assume that should not be relevant, because I was testing the board...

Hi all

i have a 2338 which had no display (there is a little crack near the edge to the case) but worked with external display. Some weeks later it didn`t boot anymore.
USB Tester shows 5,18v, 0,08 a and 0,38w with power supply.
With battery connected i get 20v and 0,0 a
Thermal camera shows that U0500 is heating up to 30c.

F5200 is not shorted
Visual inspection didn't show any problems.

I'm sure that i need to change the display but what can i do to find my other problem with the board?...

[FONT=Calibri]Hello,[/FONT]
[FONT=Calibri]I am currently working on a Macbook Pro [B]A1990 [/B](motherboard [B]820-01041[/B]) which is not charging.[/FONT]
[FONT=Calibri]The Macbook consumes 5V and 0.019A at USB-C. There seems to be a partial [B]short-circuit[/B] on the [B]PPBUS_G3H [/B]rail as I have 0V on this rail.[/FONT]

[FONT=Calibri]I've physically separated (by removing F7000 and F7001) PPBUS_G3H and the ISL9240 charging chip to see which side the short is coming from. Removing these fuses gives me 12.6V at the output of the ISL chip (PPVBAT_G3H_CHGR_REG).[/FONT]...

Hi,

I hope this is the correct place to post about this device. I originally posted regarding this on iFixit so see the details from that post below:

"I'm hoping someone can give their opinion on the symptoms I'm seeing before I spend any more time and put money into this. I got this MacBook from a customer and after looking at it they decided they didn't want it.

It doesn't turn on and there's no visual signs of life. I have tried resetting the NVRAM, SMC, power cycling, unplugging the battery, using the charger with the battery unplugged. Removed the...

[FONT=Verdana]Hello everyone.[/FONT]

[FONT=Verdana]I have recently obtained a MacBook Pro A1989 model with a touch bar and Apple ID. Unfortunately, it does not want to start up.[/FONT]

[FONT=Verdana]No CPU Voltage.[/FONT]
[FONT=Verdana]U7800 Does produce voltages.[/FONT]
[FONT=Verdana]T2 Chip warming up very very little.[/FONT]

[FONT=Verdana]I do have voltages like 1.8, 0.9, 3.3, 2.5 volts, etc., present. I did not find any short circuits. Unfortunately, the device has no touch ID/start button. So, I have used the debug jumper to put the device...