crumblenaut
New member
Hey folks! I have a no POST 16in MacBook Pro. Specifically, at the moment, I see the most obvious problem to be that I have no PPVCCPRIMCORE_PRIM_REG / PP1V05_PRIM voltage output from U7800.
I'm reading 51.9 ohms to ground and have a diode mode reading of 0.051V L7821/L7822/R7821.
All other voltages surround U7800 are present as expected.
Is the PPVCCPRIMCORE_PRIM line generated exclusively from U7800 without an enable or is there something I can backtrace to find out why that line isn't turning on?
If it SHOULD be giving output, should I just swap a PMIC from a donor?
I see that BUCK8_SW2 gets PP1V05_S3, but that's not present on my board, and I wouldn't expect it to be. What is the function of the SW lines? They're not functionally equivalent to enables, right?
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More background about the system in case the above is just a red herring - all written before I found that the main PP1V05_PRIM line that powers the PCH:
This is a 16in 820-01700 that I've been working on on and off for ages now. I have it to a point where it's at 20V, 0.05a consistently with no battery connected. It had a nasty liquid spill but is all cleaned up and lookin good IMO. PPBUS is at 12.6V.
Primary goal is data recovery, secondary goal is full repair. SSD0 and SSD1 PPBUS_G3H_SSD, 2.7V, 1.8V, and 0.9V rails are all solid.
When the battery is connected, it charges its battery properly. when doing so.
No obvious response from the power button apart from SMC resets which will drop the system out of AC2 briefly so I know it's registering.
If I give it USB power from an OEM 96W block to its rear left port and connect its front left port to my system running AC2 it defaults into Recovery mode, and revives will run successfully (or complete without notice or errors). With the battery disconnected during these recovery mode revives, current draw goes to ~1.5-2A, the CPU heats up, and the fans spin hard - both of which I consider good signs - but it doesn't give any display or backlight and when the process completes it goes back to 20V @ 0.05A and, if still connected to AC2, shows up as in Recovery mode.
The board can load into DFU mode but revive attempts kick back AMRestoreErrorDomain - 0x6.
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Thank you for any insight you can offer!!!
I'm reading 51.9 ohms to ground and have a diode mode reading of 0.051V L7821/L7822/R7821.
All other voltages surround U7800 are present as expected.
Is the PPVCCPRIMCORE_PRIM line generated exclusively from U7800 without an enable or is there something I can backtrace to find out why that line isn't turning on?
If it SHOULD be giving output, should I just swap a PMIC from a donor?
I see that BUCK8_SW2 gets PP1V05_S3, but that's not present on my board, and I wouldn't expect it to be. What is the function of the SW lines? They're not functionally equivalent to enables, right?
---------------------------------------------------------------------------------------
More background about the system in case the above is just a red herring - all written before I found that the main PP1V05_PRIM line that powers the PCH:
This is a 16in 820-01700 that I've been working on on and off for ages now. I have it to a point where it's at 20V, 0.05a consistently with no battery connected. It had a nasty liquid spill but is all cleaned up and lookin good IMO. PPBUS is at 12.6V.
Primary goal is data recovery, secondary goal is full repair. SSD0 and SSD1 PPBUS_G3H_SSD, 2.7V, 1.8V, and 0.9V rails are all solid.
When the battery is connected, it charges its battery properly. when doing so.
No obvious response from the power button apart from SMC resets which will drop the system out of AC2 briefly so I know it's registering.
If I give it USB power from an OEM 96W block to its rear left port and connect its front left port to my system running AC2 it defaults into Recovery mode, and revives will run successfully (or complete without notice or errors). With the battery disconnected during these recovery mode revives, current draw goes to ~1.5-2A, the CPU heats up, and the fans spin hard - both of which I consider good signs - but it doesn't give any display or backlight and when the process completes it goes back to 20V @ 0.05A and, if still connected to AC2, shows up as in Recovery mode.
The board can load into DFU mode but revive attempts kick back AMRestoreErrorDomain - 0x6.
---------------------------------------------------------------------------------------
Thank you for any insight you can offer!!!
