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820-1949-A dead board
- Thread starter Soji
- Start date
Any fault history, liquid sign?
"U6903 it has it’s power which is PPVIN_G3H_P3V3G3HRTC"
Wrong assumption; U6903 power is PPVIN_G3H_P3V3G3HRTC_R!
Don't you consider to check R6900???
"U6903 it has it’s power which is PPVIN_G3H_P3V3G3HRTC"
Wrong assumption; U6903 power is PPVIN_G3H_P3V3G3HRTC_R!
Don't you consider to check R6900???
Soji
Member
No history, board just came in dead, apologies I miss the last R because I took measurements on C6907 and C6906 which are connected to pin 2 of R6900 and they were good 12.3V just to double check my readings, what about the Enable signal CHGR_EN_MVR_R?? Is 5V a good one??
Last edited:
5V is good there.
Diode mode to ground at L6900?
If good, check R6910-13 and C6903/10.
If all good, then change U6903.
Diode mode to ground at L6900?
If good, check R6910-13 and C6903/10.
If all good, then change U6903.
Soji
Member
Recap
Board came in dead drawing 5V, PPBUS is present and 12.3V,
but PP3V3_G3H_RTC is not present,
I checked U6903 it has it’s power which is PPVIN_G3H_P3V3G3H_RTC_R which is 12.3V and the enable signal CHGR_EN_ MVR_R is 5V, Which was also confirmed to be good by you. Changed IC U6903 and PP3V3_G3H_ RTC was present and board daws 20V from type c charger.
**Now the system came up but getting very hot and shot down( I guessed a thermal shot down)
**I had to resit the board in the casing,
Now it’s just showing the apple logo without loading the progress bar
** I restored it with configurator 2, it was restored successfully
** now it’s stocked on internet recovery,is not loading any progress bar. Internet recovery is not loading
Board came in dead drawing 5V, PPBUS is present and 12.3V,
but PP3V3_G3H_RTC is not present,
I checked U6903 it has it’s power which is PPVIN_G3H_P3V3G3H_RTC_R which is 12.3V and the enable signal CHGR_EN_ MVR_R is 5V, Which was also confirmed to be good by you. Changed IC U6903 and PP3V3_G3H_ RTC was present and board daws 20V from type c charger.
**Now the system came up but getting very hot and shot down( I guessed a thermal shot down)
**I had to resit the board in the casing,
Now it’s just showing the apple logo without loading the progress bar
** I restored it with configurator 2, it was restored successfully
** now it’s stocked on internet recovery,is not loading any progress bar. Internet recovery is not loading
Can you start Diagnostic mode?
Also try in safe mode.
Also try in safe mode.
Start disconnecting cables from MLB, one by one; trackpad, touchbar, touch ID, etc.
See if at any moment progress bar appears.
You can disconnect even internal LCD, testing with external monitor.
See if at any moment progress bar appears.
You can disconnect even internal LCD, testing with external monitor.
Soji
Member
I discovered I didn’t fix the battery well. So I have done the needful
Now I got the internet recovery progress bar, but The processor gets very hot and the screen will goes blank with glitches on top of the screen. After like 2minutes
In short the processor gets hot when the system is working well.
Now I got the internet recovery progress bar, but The processor gets very hot and the screen will goes blank with glitches on top of the screen. After like 2minutes
In short the processor gets hot when the system is working well.
Check if heatsink does its job; try known good one.
Both fans go to max then?
Both fans go to max then?
Try again DFU restore.
Disconnect internal LCD and check if external video is affected too.
Check CPU temps with HWMonitor.
Disconnect internal LCD and check if external video is affected too.
Check CPU temps with HWMonitor.